Kenneth L. Sokoloff
B. Zorina Khan
University of California
Northeastern University
Los Angeles

I. Introduction

The antebellum period was characterized by a remarkable expansion, the sources of which are still not entirely explained. While it is clear that early economic growth was associated with rapid technical change, an enduring tradition attributes such change to exogenous breakthroughs in technology, and concomitant "great inventions". Scholars of this persuasion have argued that inventions are independent of industrial demand, with truly significant advances regarded as exogenous with respect to economic returns, or else related to individual characteristics including education, technical knowledge or genius. In contrast, we argue that the rate and direction of inventive activity during the early industrial period was influenced by propitious market conditions leading to higher expected returns, which induced relatively ordinary individuals to make investments in inventive activity. We also find a marked geographic clustering in the locus of inventive activity for "great inventors" as well as for ordinary patentees. Such activity would be economically ineffectual unless translated through innovation into productivity gains, hence we also examine the relationship between productivity and the patterns of invention which are here outlined.

II. The Characteristics of "Great Inventors" and their Patenting

The absence of systematic evidence has constituted a major obstacle in deciding between competing hypotheses, but a new set of detailed information which we have assembled may help to remedy this deficiency. Our sample of "great inventors" consists of 160 individuals drawn primarily from the Dictionary of American Biography and from accounts of technological development which credited them with an important invention between 1790 and 1846. The information includes complete patent histories through 1865, as well as place and date of birth, schooling, occupation before and after major inventions, and efforts to extract income from their discoveries, among other variables. The 150 "great inventors" who were also patentees received 1178 patents, or slightly less than 1 percent of the total awarded over the period.

One of the prominent features of the records for the great inventors is how similar some of their patterns of patenting were to those of ordinary patentees. Most significant, perhaps, is the finding that important inventions resembled patents in being strongly and positively associated with the extent of markets. Like patentees in general, the great inventors were disproportionately concentrated in the Northeast, and especially in Southern New England and New York, where low-cost transportation networks had facilitated a rapid expansion of commerce early in the antebellum period. This geographic distribution was characteristic of where they filed their patents as well as where they were born. The correspondence holds not only at the state level, but also at the county level, where great inventors were even more concentrated than the ordinary patentees in counties with high rates of general patenting.

The pro-cyclicality of both great inventor patents and overall patents during the antebellum period provides further support for the thesis that inventive activity responded to market conditions. The two annual series track each other closely, with rapid growth during the years of interruptions in foreign trade prior to the War of 1812, as well as during the economic expansions from the early 1820s to the mid-1830s, and in the 1850s. Moreover, they both exhibit periods of stagnation or slight decline during the protracted economic downturns following the War of 1812 and the Panic of 1837. This evidence indicates that, far from being exogenous, inventive activity by great inventors was influenced by much the same market-related forces as invention by ordinary patentees.

In previous work we have argued that both the pro- cyclicality and the geographic clustering of patenting in areas with low-cost access to major economic centers were consistent with the responsiveness of inventive activity to market conditions during early industrialization. It is of course possible that the clustering was partially due to geographic variation in population characteristics related to inventive potential, such as the level of education or the distribution of technical skills. Judging from the experience of the great inventors, however, such supply-side variables do not offer much explanatory power. Higher education was hardly a necessary prerequisite for important technological discovery. Nearly half of the sample had little or no formal schooling, while less than a quarter had attended college. The shares of great inventor patents were even more weighted towards those with limited schooling, since they produced larger numbers of patents on average than their more erudite peers. This qualitative pattern held over time through 1865, in all sectors and for virtually all sub-regions, with patentees from the South and foreign countries providing the only exceptions. As such, it is highly unlikely that this factor could explain geographic differences in rates of invention. Rather than unmaterialistic geniuses, age and career profiles reveal that important inventions of the period were the product of experienced and committed individuals with extensive inventive careers, who were adept in identifying and responding to market opportunities.

The occupational distribution for great inventors is likewise similar to that for ordinary patentees. Roughly one-third of our sample of great inventors was comprised of machinists, engineers and full-time inventors. The majority, however, consisted of merchants, manufacturers, farmers, and others whose jobs did not require technical skills; artisans from traditional crafts like silversmiths and engravers accounted for the remainder. As in our earlier study, one is impressed with how broad a spectrum of the population was participating in invention. Technical backgrounds and skills provided an evident advantage, especially in the transportation sector, but the nature of technology at the time was such that they were far from indispensable even for `great inventions'. Skepticism about the idea that such population characteristics account for regional patterns is reinforced by the observation that great inventors in Southern New England were markedly less well-educated and less inclined towards technical occupations than their counterparts in areas with lower inventive activity such as the Southern Middle Atlantic and the South. The evidence on great inventors conforms well with the view that high regional inventiveness was associated with a wider segment of the population directing their resources towards invention and innovation, possibly in response to higher expected returns as markets expanded.

As we have discussed elsewhere, in contrast to the paradigm of the technically-adept inventor revolutionizing an industry, our sample appears to be primarily composed of entrepreneurial inventors who contrived "schemes of practical utility". Invention was closely linked with innovation and productivity gains through entrepreneurial behavior, as individuals migrated to centers of manufacturing and invention in townships such as Hartford, Lowell, Waterbury and Trenton. Amongst an extremely mobile population, the great inventors stood out as especially inclined to take advantage of opportunities by moving - with the most mobile tending to be the most prolific in terms of numbers of patents. More than 80 percent of the great inventors at some point filed a patent in a state other than that of their birth, with over 10 percent filing in three states.

Although the number of migrant inventors is significant, the patterns of their origins and destinations are even more illuminating. Migrants clearly dominated patenting in all sub- regions except Southern New England and the Southern Middle Atlantic. The record for Southern New England is particularly interesting, since it implies that the technological leadership of this region was based on natives to the area, as opposed to centers like New York City, which attracted inventors from distant and disparate locations. The evidence suggests that the net flow of great inventors was from sub-regions with less commercial development and economic opportunity (like Northern New England or the Southern Middle Atlantic), toward areas with more extensive markets (like New York or Southern New England), or those undergoing rapid expansion (the Midwest).

The distributions further show a substantive absolute and proportional (relative to the population) net flow of great inventors toward counties with high patenting rates. These latter counties produced a disproportionate share of great inventors and would have had somewhat high patenting rate regardless, but the migrants were responsible for a large percentage of their patents, especially in major urban centers. The nature of the geographic clustering is especially striking: we find that a particular set of counties, which had attained a lead in invention early on during the industrial take-off of the 1820s, increased their advantage over time. The ranks of inventive forerunners thus maintained a relatively stable composition up to 1860.

While intriguing, an obvious issue is the question of what do these patterns add to our knowledge of efficiency gains during the period. We find that productivity was generally higher in locations with higher patenting rates such as Southern New England, and especially in those counties in which the great inventors were clustered. At the other end of the spectrum, rural Pennsylvania and Northern New England counties evinced both the lowest manufacturing productivity and lowest per capita patenting rates in the Northeast. In counties featuring higher patenting and productivity rates, the great inventors were overrepresented relative to ordinary patentees as well as to the population, and their share became even more disproportionate over the end of the 1845-1865 period. The implication is that the link between ordinary rates of patenting and productivity was even stronger in the case of great inventor patents. Overall, the results support the interpretation of patenting rates as reflective of inventive activity and of other efforts to improve efficiency.

These systematic patterns at the county level militate against the idea that important inventions were random, and instead suggest a motive factor common to both marginal improvements and important inventions. While access to markets was clearly important in this process of cumulative progress, other factors may be adduced to explain the dominance of regions such as Massachusetts and the Connecticut River Valley over the four decades prior to the Civil War, and even after. Possible elements of a complete explanation include location-specific factors such as capital enhancements, or intangible variables reflecting slowly evolving cultural and socio-economic factors. Whatever the reasons, the unprecedented mobilization of effort into patenting activity by the "great inventors" as well as by less eminent contributors clearly resulted in productivity gains and industrial expansion during the antebellum period.