Category Archives: Innovation

“Patents as a Spur to Subsequent Innovation: Evidence from Pharmaceuticals,” D. Gilchrist (2016)

Many economists of innovation are hostile to patents as they currently stand: they do not seem to be important drivers of R&D in most industries, the market power they lead to generates substantial deadweight loss, the legal costs around enforcing patents are incredible, and the effect on downstream innovation can be particularly harmful. The argument for patents seems most clear cut in industries where the invention requires large upfront fixed costs of R&D that are paid only by the first inventor, where the invention is clearly delineated, where novelty is easy to understand, and where alternative means of inducing innovation (such as market power in complementary markets, or a large first mover advantage) do not exist. The canonical example of an industry of this type is pharma.

Duncan Gilchrist points out that the market power a patentholder obtains also affects the rents of partial substitutes which might be invented later. Imagine there is a blockbuster statin on patent. If I invent a related drug, the high price of the existing patented drug means I can charge a fairly high price too. If the blockbuster drug were off patent, though, my competitors would be generics whose low price would limit how much I can charge. In other words, the “effective” patent strength in terms of the markup I can charge depends on whether alternatives to my new drug are on patent or are generic. Therefore, the profits I will earn from my drug will be lower when alternative generics exist, and hence my incentive to pay a fixed cost to create the new drug will also be lower.

What does this mean for welfare? A pure “me-too” imitation drug, which generates very little social value compared to the existing patented drug, will never enter if its class is going to see generics in a few years anyway; profits will be competed down to zero. That same drug might find it worthwhile to pay a fixed cost of invention and earn duopoly profits if the existing on patent alternative had many years of patent protection remaining. On the other hand, a drug so much better than existing drugs that even at the pure monopoly price most consumers would prefer it to the existing alternative priced at marginal cost will be developed no matter what, since it faces no de facto restriction on its markup from whether the alternatives in its drug class are generics or otherwise. Therefore, longer patent protection from existing drugs increases entry of drugs in the same class, but mainly those that are only a bit better than existing drugs. This may be better or worse for welfare: there is a wasteful costs of entering with a drug only slightly better than what exists (the private return includes the business stealing, while social welfare doesn’t), but there are also lower prices and perhaps some benefit from variety.

I should note a caveat that really should have been noted in the existing model: changes in de facto patent length for the first drug in class also affect the entry decision of that drug. Longer patent protection may actually cause shorter effective monopoly by inducing entry of imitators! This paper is mainly empirical, so no need for a full Aghion Howitt ’92 model of creative destruction, but it is at least worth noting that the welfare implications of changes in patent protection are somewhat misstated because of this omission.

Empirically, Gilchrist shows clearly that the beginning of new clinical trials for drugs falls rapidly as the first drug in their class has less time remaining on patent: fear of competition with generic partial substitutes dulls the incentive to innovate. The results are clear in straightforward scatterplots, but there is also an IV, to help confirm the causal interpretation, using the gap between the first potentially-defensive patent on the fulcrum patent of the eventual drug, and the beginning of clinical trials, a gap that is driven by randomness in things like unexpected delays in in-house laboratory progress. Using the fact that particularly promising drugs get priority FDA review, Gilchrist also shows that these priority review entrants do not seem to be worried at all about competition from generic substitutes: the “me-too” type of drugs are the ones for whom alternatives going off patent is most damaging to profits.

Final published version in AEJ: Applied 8(4) (No RePEc IDEAS version). Gilchrist is a rare example of a well published young economist working in the private sector; he has a JPE on social learning and a Management Science on behavioral labor in addition to the present paper, but works at robo-investor Wealthfront. In my now six year dataset of the economics job market (which I should discuss again at some point), roughly 2% of “job market stars” wind up outside academia. Budish, Roin and Williams used the similar idea of investigating the effect of patents of innovation by taking advantage of the differing effective patent length drugs for various maladies get as a result of differences in the length of clinical trials following the patent grant. Empirical work on the effect of patent rules is, of course, very difficult since de jure patent strength is very similar in essentially every developed country and every industry; taking advantage of differences in de facto strength is surely a trick that will be applied more broadly.

“Scale versus Scope in the Diffusion of New Technology,” D. Gross (2016)

I am spending part of the fall down at Duke University visiting the well-known group of innovation folks at Fuqua and co-teaching a PhD innovation course with Wes Cohen, who you may know via his work on Absorptive Capacity (EJ, 1989), the “Carnegie Mellon” survey of inventors with Dick Nelson and John Walsh, and his cost sharing R&D argument (article gated) with Steven Klepper. Last week, the class went over a number of papers on the diffusion of technology over space and time, a topic of supreme importance in the economics of innovation.

There are some canonical ideas in diffusion. First, cumulative adoption on the extensive margin – are you or your firm using technology X – follows an S-curve, rising slowly, then rapidly, then slowly again until peak adoption is reached. This fact is known to economists thanks to Griliches 1957 but the idea was initially developed by social psychologists and sociologists. Second, there are massive gaps in the ability of firms and nations to adopt and quickly diffuse new technologies – Diego Comin and Burt Hobijn have written a great deal on this problem. Third, the reason why technologies are slow to adopt depends on many factors, including social learning (e.g., Conley and Udry on pineapple growing in Ghana), pure epidemic-style network spread (the “Bass model”), capital replacement, “appropriate technologies” arriving once conditions are appropriate, and many more.

One that is very much underrated, however, is that technologies diffuse because they and their complements change over time. Dan Gross from HBS, another innovation scholar who likes delving into history, has a great example: the early tractor. The tractor was, in theory, invented in the 1800s, but was uneconomical and not terribly useful. With an invention by Ford in the 1910s, tractors began to spread, particularly among the US wheat belt. The tractor eventually spreads to the rest of the Midwest in the late 1920s and 1930s. A back-of-the-envelope calculation by Gross suggests the latter diffusion saved something like 10% of agricultural labor in the areas where it spread. Why, then, was there such a lag in many states?

There are many hypotheses in the literature: binding financial constraints, differences in farm sizes that make tractors feasible in one area and not another, geographic spread via social learning, and so on. Gross’ explanation is much more natural: early tractors could not work with crops like corn, and it wasn’t until after a general purpose tractor was invented in the 1920s that complementary technologies were created allowing the tractor to be used on a wide variety of farms. The charts are wholly convincing on this point: tractor diffusion time is very much linked to dominant crop, the early tractor “skipped” geographies where were inappropriate, and farms in areas where tractors diffused late nonetheless had substantial diffusion of automobiles, suggesting capital constraints were not the binding factor.

But this leaves one more question: why didn’t someone modify the tractor to make it general purpose in the first place? Gross gives a toy model that elucidates the reason quite well. Assume there is a large firm that can innovate on a technology, and can either develop a general purpose or applied versions of the technology. Assume that there is a fringe of firms that can develop complementary technology to the general purpose one (a corn harvester, for instance). If the large firm is constrained in how much innovation it can perform at any one time, it will first work on the project with highest return. If the large firm could appropriate the rents earned by complements – say, via a licensing fee – it would like to do so, but that licensing fee would decrease the incentive to develop the complements in the first place. Hence the large firm may first work on direct applications where it can capture a larger share of rents. This will imply that technology diffuses slowly first because applications are very specialized, then only as the high-return specialties have all been developed will it become worthwhile to shift researchers over to the general purpose technology. The general purpose technology will induce complements and hence rapid diffusion. As adoption becomes widespread, the rate of adoption slows down again. That is, the S-curve is merely an artifact of differing incentives to change the scope of an invention. Much more convincing that reliance on behavioral biases!

2016 Working Paper (RePEc IDEAS version). I have a paper with Jorge Lemus at Illinois on the problem of incentivizing firms to work on the right type of project, and the implications thereof. We didn’t think in terms of product diffusion, but the incentive to create general purpose technologies can absolutely be added straight into a model of that type.

“Inventing Prizes: A Historical Perspective on Innovation Awards and Technology Policy,” B. Z. Khan (2015)

B. Zorina Khan is an excellent and underrated historian of innovation policy. In her new working paper, she questions the shift toward prizes as an innovation inducement mechanism. The basic problem economists have been grappling with is that patents are costly in terms of litigation, largely due to their uncertainty, that patents impose deadweight loss by granting inventors market power (as noted at least as far back as Nordhaus 1969), and that patent rights can lead to an anticommons which in some cases harms follow-on innovation (see Scotchmer and Green and Bessen and Maskin for the theory, and papers like Heidi Williams’ genome paper for empirics).

There are three main alternatives to patents, as I see them. First, you can give prizes, determined ex-ante or ex-post. Second, you can fund R&D directly with government, as the NIH does for huge portions of medical research. Third, you can rely on inventors accruing rents to cover the R&D without any government action, such as by keeping their invention secret, relying on first mover advantage, or having market power in complementary goods. We have quite a bit of evidence that the second, in biotech, and the third, in almost every other field, is the primary driver of innovative activity.

Prizes, however, are becoming more and more common. There are X-Prizes for space and AI breakthroughs, advanced market commitments for new drugs with major third world benefits, Kremer’s “patent buyout” plan, and many others. Setting the prize amount right is of course a challenging project (one that Kremer’s idea partially fixes), and in this sense prizes run “less automatically” than the patent system. What Khan notes is that prizes have been used frequently in the history of innovation, and were frankly common in the late 18th and 19th century. How useful were they?

Unfortunately, prizes seem to have suffered many problems. Khan has an entire book on The Democratization of Invention in the 19th century. Foreign observers, and not just Tocqueville, frequently noted how many American inventors came from humble backgrounds, and how many “ordinary people” were dreaming up new products and improvements. This frenzy was often, at the time, credited to the uniquely low-cost and comprehensive U.S. patent system. Patents were simple enough, and inexpensive enough, to submit that credit for and rights to inventions pretty regularly flowed to people who were not politically well connected, and for inventions that were not “popular”.

Prizes, as opposed to patents, often incentivized the wrong projects and rewarded the wrong people. First, prizes were too small to be economically meaningful; when the well-named Hippolyte Mège-Mouriès made his developments in margarine and garnered the prize offered by Napoleon III, the value of that prize was far less than the value of the product itself. In order to shift effort with prizes, the prize designer needs to know both enough about the social value of the proposed invention to set the prize amount high enough, and enough about the value of alternatives that the prize doesn’t distort effort away from other inventions that would be created while relying solely on trade secrecy and first mover advantage (I discuss this point in much greater depth in my Direction of Innovation paper with Jorge Lemus). Providing prizes to only some inventions may either generate no change in behavior at all because the prize is too small compared with the other benefits of inventing, or cause inefficient distortions in behavior. Even though, say, a malaria vaccine would be very useful, an enormous prize for a malaria vaccine will distort health researcher effort away from other projects in a way that is tough to calculate ex-ante without a huge amount of prize designer knowledge.

There is a more serious problem with prizes. Because the cutoff for a prize is less clear cut, there is more room for discretion and hence a role for wasteful lobbying and personal connection to trump “democratic invention”. Khan notes that even though the French buyout of Daguerre’s camera patent is cited as a classic example of a patent buyout in the famous Kremer QJE article, it turns out that Daguerre never actually held any French patent at all! What actually happened was that Daguerre lobbied the government for a sinecure in order to make his invention public, but then patented it abroad anyway! There are many other political examples, such as the failure of the uneducated clockmaker John Harrison to be granted a prize for his work on longitude due partially to the machinations of more upper class competitors who captured the ear of the prize committee. Examining a database of great inventors on both sides of the Atlantic, Khan found that prizes were often linked to factors like overcoming hardship, having an elite education, or regional ties. That is, the subjectivity of prizes may be stronger than the subjectivity of patents.

So then, we have three problems: prize designers don’t know enough about the relative import of various ideas to set price amounts optimally, prizes in practice are often too small to have much effect, and prizes lead to more lobbying and biased rewards than patents. We shouldn’t go too far here; prizes still may be an important part of the innovation policy toolkit. But the history Khan lays out certainly makes me more sanguine that they are a panacea.

One final point. I am unconvinced that patents really help the individual or small inventor very much either. I did a bit of hunting: as far as I can tell, there is not a single billionaire who got that way primarily by selling their invention. Many people developed their invention in a firm, but non-entrepreneurial invention, for which the fact that patents create a market for knowledge is supposedly paramount, doesn’t seem to be making anyone super rich. This is even though there are surely a huge number of inventions each worth billions. A good defense of patents as our main innovation policy should really grapple better with this fact.

July 2015 NBER Working Paper (RePEc IDEAS). I’m afraid the paper is gated if you don’t have an NBER subscription, and I was unable to find an ungated copy.

“Editor’s Introduction to The New Economic History and the Industrial Revolution,” J. Mokyr (1998)

I taught a fun three hours on the Industrial Revolution in my innovation PhD course this week. The absolutely incredible change in the condition of mankind that began in a tiny corner of Europe in an otherwise unremarkable 70-or-so years is totally fascinating. Indeed, the Industrial Revolution and its aftermath are so important to human history that I find it strange that we give people PhDs in social science without requiring at least some study of what happened.

My post today draws heavily on Joel Mokyr’s lovely, if lengthy, summary of what we know about the period. You really should read the whole thing, but if you know nothing about the IR, there are really five facts of great importance which you should be aware of.

1) The world was absurdly poor from the dawn of mankind until the late 1800s, everywhere.
Somewhere like Chad or Nepal today fares better on essentially any indicator of development than England, the wealthiest place in the world, in the early 1800s. This is hard to believe, I know. Life expectancy was in the 30s in England, infant mortality was about 150 per 1000 live births, literacy was minimal, and median wages were perhaps 3 to 4 times subsistence. Chad today has a life expectancy of 50, infant mortality of 90 per 1000, a literacy of 35%, and urban median wages of roughly 3 to 4 times subsistence. Nepal fares even better on all counts. The air from the “dark, Satanic mills” of William Blake would have made Beijing blush, “night soil” was generally just thrown on to the street, children as young as six regularly worked in mines, and 60 to 80 hours a week was a standard industrial schedule.


The richest places in the world were never more than 5x subsistence before the mid 1800s

Despite all of this, there was incredible voluntary urbanization: those dark, Satanic mills were preferable to the countryside. My own ancestors were among the Irish that fled the Potato famine. Mokyr’s earlier work on the famine, which happened in the British Isles after the Industrial Revolution, suggest 1.1 to 1.5 million people died from a population of about 7 million. This is similar to the lower end of the range for percentage killed during the Cambodian genocide, and similar to the median estimates of the death percentage during the Rwandan genocide. That is, even in the British Isles, famines that would shock the world today were not unheard of. And even if you wanted to leave the countryside, it may have been difficult to do so. After Napoleon, serfdom remained widespread east of the Elbe river in Europe, passes like the “Wanderbucher” were required if one wanted to travel, and coercive labor institutions that tied workers to specific employers were common. This is all to say that the material state of mankind before and during the Industrial Revolution, essentially anywhere in the world, would be seen as outrageous deprivation to us today; palaces like Versailles are not representative, as should be obvious, of how most people lived. Remember also that we are talking about Europe in the early 1800s; estimates of wages in other “rich” societies of the past are even closer to subsistence.

2) The average person did not become richer, nor was overall economic growth particularly spectacular, during the Industrial Revolution; indeed, wages may have fallen between 1760 and 1830.

The standard dating of the Industrial Revolution is 1760 to 1830. You might think: factories! The railroad! The steam engine! High Britannia! How on Earth could people have become poorer? And yet it is true. Brad DeLong has an old post showing Bob Allen’s wage reconstructions: Allen found British wages lower than their 1720 level in 1860! John Stuart Mill, in his 1870 textbook, still is unsure whether all of the great technological achievements of the Industrial Revolution would ever meaningfully improve the state of the mass of mankind. And Mill wasn’t the only one who noticed, there were a couple of German friends, who you may know, writing about the wretched state of the Working Class in Britain in the 1840s as well.

3) Major macro inventions, and growth, of the type seen in England in the late 1700s and early 1800s happened many times in human history.


The Iron Bridge in Shropshire, 1781, proving strength of British iron

The Industrial Revolution must surely be “industrial”, right? The dating of the IR’s beginning to 1760 is at least partially due to the three great inventions of that decade: the Watt engine, Arkwright’s water frame, and the spinning jenny. Two decades later came Cort’s famous puddling process for making strong iron. The industries affected by those inventions, cotton and iron, are the prototypical industries of England’s industrial height.

But if big macro-inventions, and a period of urbanization, are “all” that defines the Industrial Revolution, then there is nothing unique about the British experience. The Song Dynasty in China saw the gun, movable type, a primitive Bessemer process, a modern canal lock system, the steel curved moldboard plow, and a huge increase in arable land following public works projects. Netherlands in the late 16th and early 17th century grew faster, and eventually became richer, than Britain ever did during the Industrial Revolution. We have many other examples of short-lived periods of growth and urbanization: ancient Rome, Muslim Spain, the peak of the Caliphate following Harun ar-Rashid, etc.

We care about England’s growth and invention because of what followed 1830, not what happened between 1760 and 1830. England was able to take their inventions and set on a path to break the Malthusian bounds – I find Galor and Weil’s model the best for understanding what is necessary to move from a Malthusian world of limited long-run growth to a modern world of ever-increasing human capital and economic bounty. Mokyr puts it this way: “Examining British economic history in the period 1760-1830 is a bit like studying the history of Jewish dissenters between 50 B.C. and 50 A.D. At first provincial, localized, even bizarre, it was destined to change the life of every man and women…beyond recognition.”

4) It is hard for us today to understand how revolutionary ideas like “experimentation” or “probability” were.

In his two most famous books, The Gifts of Athena and The Lever of Riches, Mokyr has provided exhausting evidence about the importance of “tinkerers” in Britain. That is, there were probably something on the order of tens of thousands of folks in industry, many not terribly well educated, who avidly followed new scientific breakthroughs, who were aware of the scientific method, who believed in the existence of regularities which could be taken advantage of by man, and who used systematic processes of experimentation to learn what works and what doesn’t (the development of English porter is a great case study). It is impossible to overstate how unusual this was. In Germany and France, science was devoted mainly to the state, or to thought for thought’s sake, rather than to industry. The idea of everyday, uneducated people using scientific methods somewhere like ar-Rashid’s Baghdad is inconceivable. Indeed, as Ian Hacking has shown, it wasn’t just that fundamental concepts like “probabilistic regularities” were difficult to understand: the whole concept of discovering something based on probabilistic output would not have made sense to all but the very most clever person before the Enlightenment.

The existence of tinkerers with access to a scientific mentality was critical because it allowed big inventions or ideas to be refined until they proved useful. England did not just invent the Newcomen engine, put it to work in mines, and then give up. Rather, England developed that Newcomen engine, a boisterous monstrosity, until it could profitably be used to drive trains and ships. In Gifts of Athena, Mokyr writes that fortune may sometimes favor the unprepared mind with a great idea; however, it is the development of that idea which really matters, and to develop macroinventions you need a small but not tiny cohort of clever, mechanically gifted, curious citizens. Some have given credit to a political system, or to the patent system, for the widespread tinkering, but the qualitative historical evidence I am aware of appears to lean toward cultural explanations most strongly. One great piece of evidence is that contemporaries wrote often about the pattern where Frenchmen invented something of scientific importance, yet the idea diffused and was refined in Britain. Any explanation of British uniqueness must depend on Britain’s ability to refine inventions.

5) The best explanations for “why England? why in the late 1700s? why did growth continue?” do not involve colonialism, slavery, or famous inventions.

First, we should dispose of colonialism and slavery. Exports to India were not particularly important compared to exports to non-colonial regions, slavery was a tiny portion of British GDP and savings, and many other countries were equally well-disposed to profit from slavery and colonialism as of the mid-1700s, yet the IR was limited to England. Expanding beyond Europe, Dierdre McCloskey notes that “thrifty self-discipline and violent expropriation have been too common in human history to explain a revolution utterly unprecedented in scale and unique to Europe around 1800.” As for famous inventions, we have already noted how common bursts of cleverness were in the historic record, and there is nothing to suggest that England was particularly unique in its macroinventions.

To my mind, this leaves two big, competing explanations: Mokyr’s argument that tinkerers and a scientific mentality allowed Britain to adapt and diffuse its big inventions rapidly enough to push the country over the Malthusian hump and into a period of declining population growth after 1870, and Bob Allen’s argument that British wages were historically unique. Essentially, Allen argues that British wages were high compared to its capital costs from the Black Death forward. This means that labor-saving inventions were worthwhile to adopt in Britain even when they weren’t worthwhile in other countries (e.g., his computations on the spinning jenny). If it worthwhile to adopt certain inventions, then inventors will be able to sell something, hence it is worthwhile to invent certain inventions. Once adopted, Britain refined these inventions as they crawled down the learning curve, and eventually it became worthwhile for other countries to adopt the tools of the Industrial Revolution. There is a great deal of debate about who has the upper hand, or indeed whether the two views are even in conflict. I do, however, buy the argument, made by Mokyr and others, that it is not at all obvious that inventors in the 1700s were targeting their inventions toward labor saving tasks (although at the margin we know there was some directed technical change in the 1860s), nor it is even clear that invention overall during the IR was labor saving (total working hours increased, for instance).

Mokyr’s Editor’s Introduction to “The New Economic History and the Industrial Revolution” (no RePEc IDEAS page). He has a followup in the Journal of Economic History, 2005, examining further the role of an Enlightenment mentality in allowing for the rapid refinement and adoption of inventions in 18th century Britain, and hence the eventual exit from the Malthusian trap.

“Identifying Technology Spillovers and Product Market Rivalry,” N. Bloom, M. Schankerman & J. Van Reenen (2013)

How do the social returns to R&D differ from the private returns? We must believe there is a positive gap between the two given the widespread policies of subsidizing R&D investment. The problem is measuring the gap: theory gives us a number of reasons why firms may do more R&D than the social optimum. Most intuitively, a lot of R&D contains “business stealing” effects, where some of the profit you earn from your new computer chip comes from taking sales away from me, even if you chip is only slightly better than mine. Business stealing must be weighed against the fact that some of the benefits of knowledge a firm creates is captured by other firms working on similar problems, and the fact that consumers get surplus from new inventions as well.

My read of the literature is that we don’t have know much about how aggregate social returns to research differ from private returns. The very best work is at the industry level, such as Trajtenberg’s fantastic paper on CAT scans, where he formally writes down a discrete choice demand system for new innovations in that product and compares R&D costs to social benefits. The problem with industry-level studies is that, almost by definition, they are studying the social return to R&D in ex-post successful new industries. At an aggregate level, you might think, well, just include the industry stock of R&D in a standard firm production regression. This will control for within-industry spillovers, and we can make some assumption about the steepness of the demand curve to translate private returns given spillovers into returns inclusive of consumer surplus.

There are two problems with that method. First, what is an “industry” anyway? Bloom et al point out in the present paper that even though Apple and Intel do very similar research, as measured by the technology classes they patent in, they don’t actually compete in the product market. This means that we want to include “within-similar-technology-space stock of knowledge” in the firm production function regression, not “within-product-space stock of knowledge”. Second, and more seriously, if we care about social returns, we want to subtract out from the private return to R&D any increase in firm revenue that just comes from business stealing with slightly-improved versions of existing products.

Bloom et al do both in a very interesting way. First, they write down a model where firms get spillovers from research in similar technology classes, then compete with product market rivals; technology space and product market space are correlated but not perfectly so, as in the Apple/Intel example. They estimate spillovers in technology space using measures of closeness in terms of patent classes, and measure closeness in product space based on the SIC industries that firms jointly compete in. The model overidentifies the existence of spillovers: if technological spillovers exist, then you can find evidence conditional on the model in terms of firm market value, firm R&D totals, firm productivity and firm patent activity. No big surprises, given your intuition: technological spillovers to other firms can be seen in every estimated equation, and business stealing R&D, though small in magnitude, is a real phenomenon.

The really important estimate, though, is the level of aggregate social returns compared to private returns. The calculation is non-obvious, and shuttled to an online appendix, but essentially we want to know how increasing R&D by one dollar increases total output (the marginal social return) and how increasing R&D by one dollar increases firm revenue (marginal private return). The former may exceed the latter if the benefits of R&D spill over to other firms, but the latter may exceed the former is lots of R&D just leads to business stealing. Note that any benefits in terms of consumer surplus are omitted. Bloom et al find aggregate marginal private returns on the order of 20%, and social returns on the order of 60% (a gap referred to as “29.2%” instead of “39.2%” in the paper; come on, referees, this is a pretty important thing to not notice!). If it wasn’t for business stealing, the gap between social and private returns would be ten percentage points higher. I confess a little bit of skepticism here; do we really believe that for the average R&D performing firm, the marginal private return on R&D is 20%? Nonetheless, the estimate that social returns exceed private returns is important. Even more important is the insight that the gap between social and private returns depends on the size of the technology spillover. In Bloom et al’s data, large firms tend to do work in technology spaces with more spillovers, while small firms tend to work on fairly idiosyncratic R&D; to greatly simplify what is going on, large firms are doing more general R&D than the very product-specific R&D small firms do. This means that the gap between private and social return is larger for large firms, and hence the justification for subsidizing R&D might be highest for very large firms. Government policy in the U.S. used to implicitly recognize this intuition, shuttling R&D funds to the likes of Bell Labs.

All in all an important contribution, though this is by no means the last word on spillovers; I would love to see a paper asking why firms don’t do more R&D given the large private returns we see here (and in many other papers, for that matter). I am also curious how R&D spillovers compare to spillovers from other types of investments. For instance, an investment increasing demand for product X also increases demand for any complementary products, leads to increased revenue that is partially captured by suppliers with some degree of market power, etc. Is R&D really that special compared to other forms of investment? Not clear to me, especially if we are restricting to more applied, or more process-oriented, R&D. At the very least, I don’t know of any good evidence one way or the other.

Final version, Econometrica 2013 (RePEc IDEAS version); the paper essentially requires reading the Appendix in order to understand what is going on.

“Competition, Imitation and Growth with Step-by-Step Innovation,” P. Aghion, C. Harris, P. Howitt, & J. Vickers (2001)

(One quick PSA before I get to today’s paper: if you happen, by chance, to be a graduate student in the social sciences in Toronto, you are more than welcome to attend my PhD seminar in innovation and entrepreneurship at the Rotman school which begins on Wednesday, the 7th. I’ve put together a really wild reading list, so hopefully we’ll get some very productive discussions out of the course. The only prerequisite is that you know some basic game theory, and my number one goal is forcing the economists to read sociology, the sociologists to write formal theory, and the whole lot to understand how many modern topics in innovation have historical antecedents. Think of it as a high-variance cross-disciplinary educational lottery ticket! If interested, email me at kevin.bryanATrotman.utoronto.ca for more details.)

Back to Aghion et al. Let’s kick off 2015 with one of the nicer pieces to come out the ridiculously productive decade or so of theoretical work on growth put together by Philippe Aghion and his coauthors; I wish I could capture the famous alacrity of Aghion’s live presentation of his work, but I fear that’s impossible to do in writing! This paper is based around writing a useful theory to speak to two of the oldest questions in the economics of innovation: is more competition in product markets good or bad for R&D, and is there something strange about giving a firm IP (literally a grant of market power meant to spur innovation via excess rents) at the same time as we enforce antitrust (generally a restriction on market power meant to reduce excess rents)?

Aghion et al come to a few very surprising conclusions. First, the Schumpeterian idea that firms with market power do more R&D is misleading because it ignores the “escape the competition” effect whereby firms have high incentive to innovate when there is a large market that can be captured by doing so. Second, maximizing that “escape the competition” motive may involve making it not too easy to catch up to market technological leaders (by IP or other means). These two theoretical results imply that antitrust (making sure there are a lot of firms competing in a given market, spurring new innovation to take market share from rivals) and IP policy (ensuring that R&D actually needs to be performed in order to gain a lead) are in a sense complements! The fundamental theoretical driver is that the incentive to innovate depends not only on the rents of an innovation, but on the incremental rents of an innovation; if innovators include firms that already active in an industry, policy that makes your current technological state less valuable (because you are in a more competitive market, say) or policy that makes jumping to a better technological state more valuable both increase the size of the incremental rent, and hence the incentive to perform R&D.

Here are the key aspects of a simplified version of the model. An industry is a duopoly where consumers spend exactly 1 dollar per period. The duopolists produce partially substitutable goods, where the more similar the goods the more “product market competition” there is. Each of the duopolists produces their good at a firm-specific cost, and competes in Bertrand with their duopoly rival. At the minimal amount of product market competition, each firm earns constant profit regardless of their cost or their rival’s cost. Firms can invest in R&D which gives some flow probability of lowering their unit cost. Technological laggards sometimes catch up to the unit cost of leaders with exogenous probability; lower IP protection (or more prevalent spillovers) means this probability is higher. We’ll look only at features of this model in the stochastic distribution of technological leadership and lags which is a steady state if there infinite duopolistic industries.

In a model with these features, you always want at least a little competition, essentially for Arrow (1962) reasons: the size of the market is small when market power is large because total unit sales are low, hence the benefit of reducing unit costs is low, hence no one will bother to do any innovation in the limit. More competition can also be good because it increases the probability that two firms are at similar technological levels, in which case each wants to double down on research intensity to gain a lead. At very high levels of competition, the old Schumpeterian story might bind again: goods are so substitutable that R&D to increase rents is pointless since almost all rents are competed away, especially if IP is weak so that rival firms catch up to your unit cost quickly no matter how much R&D you do. What of the optimal level of IP? It’s always best to ensure IP is not too strong, or that spillovers are not too weak, because the benefit of increased R&D effort when firms are at similar technological levels following the spillover exceeds the lost incentive to gain a lead in the first place when IP is not perfectly strong. When markets are really competitive, however, the Schumpeterian insight that some rents need to exist militates in favor of somewhat stronger IP than in less competitive product markets.

Final working paper (RePEc IDEAS) which was published in 2001 in the Review of Economic Studies. This paper is the more detailed one theoretically, but if all of the insight sounds familiar, you may already know the hugely influential follow-up paper by Aghion, Bloom, Blundell, Griffith and Howitt, “Competition and Innovation: An Inverted U Relationship”, published in the QJE in 2005. That paper gives some empirical evidence for the idea that innovation is maximized at intermediate values of product market competition; the Schumpeterian “we need some rents” motive and the “firms innovate to escape competition” motive both play a role. I am actually not a huge fan of this paper – as an empirical matter, I’m unconvinced that most cost-reducing innovation in many industries will never show up in patent statistics (principally for reasons that Eric von Hippel made clear in The Sources of Innovation, which is freely downloadable at that link!). But this is a discussion for another day! One more related paper we have previously discussed is Goettler and Gordon’s 2012 structural work on processor chip innovation at AMD and Intel, which has a very similar within-industry motivation.

“Organizing Venture Capital: The Rise and Demise of American Research and Development Corporation, 1946-1973,” D. Hsu & M. Kenney (2005)

Venture capital financing of innovative firms feels like a new phenomenon, and is clearly of great importance to high tech companies as well as cities that hope to attract these companies. The basic principle involves relatively small numbers of wealthy individuals providing long-term financing to a group of managers who seek out early-stage, unprofitable firms, make an investment (generally equity), and occasionally help actively manage the company.

There are many other ways firms can fund themselves: issuance of equity, investment from friends or family, investment from an existing firm in a spinoff, investment from the saved funds of an individual, or debt loans from a bank, among others. Two questions, then, are immediate: why does anyone fund with VC in the first place, and how did this institutional form come about? VC is strange at first glance: in a stage in which entrepreneur effort is particularly important, why would I write a financing contract which takes away some of the upside of working hard on the part of the entrepreneur by diluting her ownership share? Two things are worth noting. VC rather than debt finance is particularly common when returns are highly skewed – a bank loan can only be repaid with interest, hence will have trouble capturing that upside. Second, early-stage equity finance and active managerial assistance appear to come bundled, hence some finance folks have argued that the moral hazard problem lies both with the entrepreneur, who must be incentivized to work hard, and with the VC firm and their employees, who need the same incentive.

Let’s set aside the question of entrepreneurial finance, and look into history. Though something like venture capital appeared to be important in the Second Industrial Revolution (see, e.g., Lamoreaux et al (2006) on that hub of high-tech, Cleveland!), and it may have existed in a proto-form as early as the 1700s with the English country banks (though I am not totally convinced of that equivalence), the earliest modern VC firm was Boston’s American Research and Development Corporation. The decline of textiles hit New England hard in the 1920s and 1930s. A group of prominent blue bloods, including the President of MIT and the future founder of INSEAD, had discussed the social need for an organization that would fund firms which could potentially lead to new industries, and they believed that despite this social goal, the organization ought be a profit-making concern if it were to be successful in the long run.

After a few false starts, the ARD formed in 1946, a time of widespread belief in the power of R&D following World War II and Vannevar Bush’s famous “Science: the Endless Frontier”. ARD was organized as a closed-end investment trust, which permitted institutional investors to contribute. Investments tended to be solicited, were very likely to be made to New England firms, and were, especially in the first few years, concentrated in R&D intensive companies; local, solicited, R&D heavy investment is even today the most common type of VC. Management was often active, and there are reports of entire management teams being replaced by ARD if they felt the firm was not growing quickly enough.

So why have you never of ARD, then? Two reasons: returns, and organizational structure. ARD’s returns over the 50s and 60s were barely higher, even before fees, than the S&P 500 as a whole. And this overstates things: an investment in Digital Equipment, the pioneering minicomputer company, was responsible for the vast majority of profits. No surprise, then, that even early VCs had highly skewed returns. More problematic was competition. A 1958 law permitted Small Business Investment Corporations (SBICs) to make VC-style investments at favorable tax rates, and the organizational form of limited partnership VC was less constrained by the SEC than a closed-end investment fund. In particular, the partnerships “2 and 20” structure meant that top investment managers could earn much more money at that type of firm than at ARD. One investment manager at ARD put a huge amount of effort into developing a company called Optical Scanning, whose IPO made the founder $10 million. The ARD employee, partially because of SEC regulations, earned a $2000 bonus. By 1973, ARD had been absorbed into another company, and was for all practical purposes defunct.

It’s particularly interesting, though, that the Boston Brahmins were right: VC has been critical in two straight resurgences in the New England economy, the minicomputer cluster of the 1960s, and the more recent Route 128 biotech cluster, both of which were the world’s largest. New England, despite the collapse of textiles, has not gone the way of the rust belt – were it a country, it would be wealthier per capita than all but a couple of microstates. And yet, ARD as a profitmaking enterprise went kaput rather quickly. Yet more evidence of the danger of being a market leader – not only can other firms avoid your mistakes, but they can also take advantage of more advantageous organizational forms and laws that are permitted or created in response to your early success!

Final published version, in Industrial and Corporate Change 2005 (RePEc IDEAS).

“Dynamic Commercialization Strategies for Disruptive Technologies: Evidence from the Speech Recognition Industry,” M. Marx, J. Gans & D. Hsu (2014)

Disruption. You can’t read a book about the tech industry without Clayton Christensen’s Innovator’s Dilemma coming up. Jobs loved it. Bezos loved it. Economists – well, they were a bit more confused. Here’s the story at its most elemental: in many industries, radical technologies are introduced. They perform very poorly initially, and so are ignored by the incumbent. These technologies rapidly improve, however, and the previously ignored entrants go on to dominate the industry. The lesson many tech industry folks take from this is that you ought to “disrupt yourself”. If there is a technology that can harm your most profitable business, then you should be the one to develop it; take Amazon’s “Lab126” Kindle skunkworks as an example.

There are a couple problems with this strategy, however (well, many problems actually, but I’ll save the rest for Jill Lepore’s harsh but lucid takedown of the disruption concept which recently made waves in the New Yorker). First, it simply isn’t true that all innovative industries are swept by “gales of creative destruction” – consider automobiles or pharma or oil, where the major players are essentially all quite old. Gans, Hsu and Scott Stern pointed out in a RAND article many years ago that if the market for ideas worked well, you would expect entrants with good ideas to just sell to incumbents, since the total surplus would be higher (less duplication of sales assets and the like) and since rents captured by the incumbent would be higher (less product market competition). That is, there’s no particular reason that highly innovative industries require constant churn of industry leaders.

The second problem concerns disrupting oneself or waiting to see which technologies will last. Imagine it is costly to investigate potentially disruptive technologies for the incumbent. For instance, selling mp3s in 2002 would have cannibalized existing CD sales at a retailer with a large existing CD business. Early on, the potentially disruptive technology isn’t “that good”, hence it is not in and of itself that profitable. Eventually, some of these potentially disruptive technologies will reveal themselves to actually be great improvements on the status quo. If that is the case, then, why not just let the entrant make these improvements/drive down costs/learn about market demand, and then buy them once they reveal that the potentially disruptive product is actually great? Presumably the incumbent even by this time still retains its initial advantage in logistics, sales, brand, etc. By waiting and buying instead of disrupting yourself, you can still earn those high profits on the CD business in 2002 even if mp3s had turned out to be a flash in the pan.

This is roughly the intuition in a new paper by Matt Marx – you may know his work on non-compete agreements – Gans and Hsu. Matt has also collected a great dataset from industry journals on every firm that ever operated in automated speech recognition. Using this data, the authors show that a policy by entrants of initial competition followed by licensing or acquisition is particularly common when the entrants come in with a “disruptive technology”. You should see these strategies, where the entrant proves the value of their technology and the incumbent waits to acquire, in industries where ideas are not terribly appropriable (why buy if you can steal?) and entry is not terribly expensive (in an area like biotech, clinical trials and the like are too expensive for very small firms). I would add that you also need complementary assets to be relatively hard to replicate; if they aren’t, the incumbent may well wind up being acquired rather than the entrant should the new technology prove successful!

Final July 2014 working paper (RePEc IDEAS). The paper is forthcoming in Management Science.

“How do Patents Affect Follow-On Innovation: Evidence from the Human Genome,” B. Sampat & H. Williams (2014)

This paper, by Heidi Williams (who surely you know already) and Bhaven Sampat (who is perhaps best known for his almost-sociological work on the Bayh-Dole Act with Mowery), made quite a stir at the NBER last week. Heidi’s job market paper a few years ago, on the effect of openness in the Human Genome Project as compared to Celera, is often cited as an “anti-patent” paper. Essentially, she found that portions of the human genome sequenced by the HGP, which placed their sequences in the public domain, were much more likely to be studied by scientists and used in tests than portions sequenced by Celera, who initially required fairly burdensome contractual steps to be followed. This result was very much in line with research done by Fiona Murray, Jeff Furman, Scott Stern and others which also found that minor differences in openness or accessibility can have substantial impacts on follow-on use (I have a paper with Yasin Ozcan showing a similar result). Since the cumulative nature of research is thought to be critical, and since patents are a common method of “restricting openness”, you might imagine that Heidi and the rest of these economists were arguing that patents were harmful for innovation.

That may in fact be the case, but note something strange: essentially none of the earlier papers on open science are specifically about patents; rather, they are about openness. Indeed, on the theory side, Suzanne Scotchmer has a pair of very well-known papers arguing that patents effectively incentivize cumulative innovation if there are no transaction costs to licensing, no spillovers from sequential research, and no incentive for early researchers to limit licenses in order to protect their existing business (consider the case of Farnsworth and the FM radio), and if potential follow-on innovators can be identified before they sink costs. That is a lot of conditions, but it’s not hard to imagine industries where inventions are clearly demarcated, where holders of basic patents are better off licensing than sitting on the patent (perhaps because potential licensors are not also competitors), and where patentholders are better off not bothering academics who technically infringe on their patent.

What industry might have such characteristics? Sampat and Williams look at gene patents. Incredibly, about 30 percent of human genes have sequences that are claimed under a patent in the United States. Are “patented genes” still used by scientists and developers of medical diagnostics after the patent grant, or is the patent enough of a burden to openness to restrict such use? What is interesting about this case is that the patentholder generally wants people to build on their patent. If academics find some interesting genotype-phenotype links based on their sequence, or if another firm develops a disease test based on the sequence, there are more rents for the patentholder to garner. In surveys, it seems that most academics simply ignore patents of this type, and most gene patentholders don’t interfere in research. Anecdotally, licenses between the sequence patentholder and follow-on innovators are frequent.

In general, it is really hard to know whether patents have any effect on anything, however; there is very little variation over time and space in patent strength. Sampat and Williams take advantage of two quasi-experiments, however. First, they compare applied-for-but-rejected gene patents to applied-for-but-granted patents. At least for gene patents, there is very little difference in terms of measurables before the patent office decision across the two classes. Clearly this is not true for patents as a whole – rejected patents are almost surely of worse quality – but gene patents tend to come from scientifically competent firms rather than backyard hobbyists, and tend to have fairly straightforward claims. Why are any rejected, then? The authors’ second trick is to look directly at patent examiner “leniency”. It turns out that some examiners have rejection rates much higher than others, despite roughly random assignment of patents within a technology class. Much of the difference in rejection probability is driven by the random assignment of examiners, which justifies the first rejected-vs-granted technique, and also suggested an instrumental variable to further investigate the data.

With either technique, patent status essentially generates no difference in the use of genes by scientific researchers and diagnostic test developers. Don’t interpret this result as turning over Heidi’s earlier genome paper, though! There is now a ton of evidence that minor impediments to openness are harmful to cumulative innovation. What Sampat and Williams tell us is that we need to be careful in how we think about “openness”. Patents can be open if the patentholder has no incentive to restrict further use, if downstream innovators are easy to locate, and if there is no uncertainty about the validity or scope of a patent. Indeed, in these cases the patentholder will want to make it as easy as possible for follow-on innovators to build on their patent. On the other hand, patentholders are legally allowed to put all sorts of anti-openness burdens on the use of their patented invention by anyone, including purely academic researchers. In many industries, such restrictions are in the interest of the patentholder, and hence patents serve to limit openness; this is especially true where private sector product development generates spillovers. Theory as in Scotchmer-Green has proven quite correct in this regard.

One final comment: all of these types of quasi-experimental methods are always a bit weak when it comes to the extensive margin. It may very well be that individual patents do not restrict follow-on work on that patent when licenses can be granted, but at the same time the IP system as a whole can limit work in an entire technological area. Think of something like sampling in music. Because all music labels have large teams of lawyers who want every sample to be “cleared”, hip-hop musicians stopped using sampled beats to the extent they did in the 1980s. If you investigated whether a particular sample was less likely to be used conditional on its copyright status, you very well might find no effect, as the legal burden of chatting with the lawyers and figuring out who owns what may be enough of a limit to openness that musicians give up samples altogether. Likewise, in the complete absence of gene patents, you might imagine that firms would change their behavior toward research based on sequenced genes since the entire area is more open; this is true even if the particular gene sequence they want to investigate was unpatented in the first place, since having to spend time investigating the legal status of a sequence is a burden in and of itself.

July 2014 Working Paper (No IDEAS version). Joshua Gans has also posted a very interesting interpretation of this paper in terms of Coasean contractability.

“Agricultural Productivity and Structural Change: Evidence from Brazil,” P. Bustos et al (2014)

It’s been a while – a month of exploration in the hinterlands of the former Soviet Union, a move up to Canada, and a visit down to the NBER Summer Institute really put a cramp on my posting schedule. That said, I have a ridiculously long backlog of posts to get up, so they will be coming rapidly over the next few weeks. I saw today’s paper presented a couple days ago at the Summer Institute. (An aside: it’s a bit strange that there isn’t really any media at SI – the paper selection process results in a much better set of presentations than at the AEA or the Econometric Society, which simply have too long of a lag from the application date to the conference, and too many half-baked papers.)

Bustos and her coauthors ask, when can improvements in agricultural productivity help industrialization? An old literature assumed that any such improvement would help: the newly rich agricultural workers would demand more manufactured goods, and since manufactured and agricultural products are complements, rising agricultural productivity would shift workers into the factories. Kiminori Matsuyama wrote a model (JET 1992) showing the problem here: roughly, if in a small open economy productivity goes up in a good you have a Ricardian comparative advantage in, then you want to produce even more of that good. A green revolution which doubles agricultural productivity in, say, Mali, while keeping manufacturing productivity the same, will allow Mali to earn twice as much selling the agriculture overseas. Workers will then pour into the agricultural sector until the marginal product of labor is re-equated in both sectors.

Now, if you think that industrialization has a bunch of positive macrodevelopment spillovers (via endogenous growth, population control or whatever), then this is worrying. Indeed, it vaguely suggests that making villages more productive, an outright goal of a lot of RCT-style microdevelopment studies, may actually be counterproductive for the country as a whole! That said, there seems to be something strange going on empirically, because we do appear to see industrialization in countries after a Green Revolution. What could be going on? Let’s look back at the theory.

Implicitly, the increase in agricultural productivity in Matsuyama was “Hicks-neutral” – it increased the total productivity of the sector without affecting the relative marginal factor productivities. A lot of technological change, however, is factor-biased; to take two examples from Brazil, modern techniques that allow for double harvesting of corn each year increase the marginal productivity of land, whereas “Roundup Ready” GE soy that requires less tilling and weeding increases the marginal productivity of farmers. We saw above that Hicks-neutral technological change in agriculture increases labor in the farm sector: workers choosing where to work means that the world price of agriculture times the marginal product of labor in that sector must be equal to world price of manufacturing times the marginal product of labor in manufacturing. A Hicks-neutral improvement in agricultural productivity raises MPL in that sector no matter how much land or labor is currently being used, hence wage equality across sectors requires workers to leave the factor for the farm.

What of biased technological change? As before, the only thing we need to know is whether the technological change increases the marginal product of labor. Land-augmenting technical change, like double harvesting of corn, means a country can produce the same amount of output with the old amount of farm labor and less land. If one more worker shifts from the factory to the farm, she will be farming less marginal land than before the technological change, hence her marginal productivity of labor is higher than before the change, hence she will leave the factory. Land-augmenting technological change always increases the amount of agricultural labor. What about farm-labor-augmenting technological change like GM soy? If land and labor are not very complementary (imagine, in the limit, that they are perfect substitutes in production), then trivially the marginal product of labor increases following the technological change, and hence the number of farm workers goes up. The situation is quite different if land and farm labor are strong complements. Where previously we had 1 effective worker per unit of land, following the labor-augmenting technology change it is as if we have, say, 2 effective workers per unit of land. Strong complementarity implies that, at that point, adding even more labor to the farms is pointless: the marginal productivity of labor is decreasing in the technological level of farm labor. Therefore, labor-augmenting technology with a strongly complementary agriculture production function shifts labor off the farm and into manufacturing.

That’s just a small bit of theory, but it really clears things up. And even better, the authors find empirical support for this idea: following the introduction to Brazil of labor-augmenting GM soy and land-augmenting double harvesting of maize, agricultural productivity rose everywhere, the agricultural employment share rose in areas that were particularly suitable for modern maize production, and the manufacturing employment share rose in areas that were particularly suitable for modern soy production.

August 2013 working paper. I think of this paper as a nice complement to the theory and empirics in Acemoglu’s Directed Technical Change and Walker Hanlon’s Civil War cotton paper. Those papers ask how changes in factor prices endogenously affect the development of different types of technology, whereas Bustos and coauthors ask how the exogenous development of different types of technology affect the use of various factors. I read the former as most applicable to structural change questions in countries at the technological frontier, and the latter as appropriate for similar questions in developing countries.

%d bloggers like this: