Changes in the demographics of American inventors, 1870–1940

We assemble a novel dataset linking inventors listed in the Annual Reports of the Commissioner of Patents to Population Census records spanning 1870 to 1940. We find that inventors are not a random subset of the population. They differ in some unsurprising ways in that they tend to be older, whiter, and more likely male. However, these patterns do change over time. The odds ratio relative to the population as a whole of female inventors increases from a low of 0.07 in 1880 to a high of 0.13 in 1940 and that of non-whites ranges from 0.16 in 1880 to 0.34 in 1940. Both populations remain severely underrepresented throughout the timeframe. We find changes in the occupations of inventors with trends away from farming and towards white collar occupations. We also show the increasing importance of foreign born people in patenting. In 1870, the odds of a foreign born person patenting relative to the population as a whole is nearly 1 and increases to over 1.6 by 1940.