Contact Information
Department of Economics
Northwestern University
2211 Campus Drive
Evanston, IL 60208
Phone (cell): 443-812-4538
Phone (office): 847-491-8250
Email: michael.andrews1@northwestern.edu
Website: www.m-andrews.com

Education
Ph.D., Economics, University of Iowa, 2017
MA, Economics, University of Iowa, 2014
BA, Economics, University of Maryland, 2011
BS, Supply Chain Management, University of Maryland, 2011

Primary Fields of Specialization
Economic History, Innovation

Secondary Fields of Specialization
Applied Microeconomics

Curriculum Vitae
Download Vita (PDF)

Job Market Paper
“The Role of Universities in Local Invention: Evidence from the Establishment of U.S. Colleges”
I exploit historical natural experiments to study how establishing a new college affects local invention. Throughout the nineteenth to the mid twentieth century, many new colleges were established in the U.S. I use data on the site selection decisions for a subset of these colleges to identify “losing finalist” locations that were strongly considered to become the site of a new college but were ultimately not chosen for plausibly exogenous reasons. The losing finalists are very similar to the winning college counties along observable dimensions. Using the losing finalists as counterfactuals, I find that the establishment of a new college caused 33% more patents per year in college counties relative to the losing finalists. To determine the channels by which colleges increase patenting, I use a novel dataset of college yearbooks and individual-level census data to learn who the additional patents in college counties come from. A college’s alumni account for about 10% of the additional patents, while faculty account for less than 1%. Knowledge spillovers to individuals unaffiliated with the college or living in the college county prior to the establishment of the new college also account for less than 1% of the additional patents. Migration is the primary channel by which colleges affect local invention, as controlling for county population accounts for 40-65% of the increase in patenting in college counties relative to the losing finalists. In spite of this, the presence of geographic spillovers suggests that colleges cause an overall net increase in patenting, although I find no evidence that colleges are better at promoting invention than other policies that lead to similar levels of urbanization.
Download Job Market Paper (PDF)

Other Research Papers
“Bar Talk: Informal Social Interactions, Alcohol Prohibition, and Invention”
To understand the importance of informal social interactions for invention, I exploit a historical policy that restricts one channel through which individuals interact. More specifically, I examine the effects of alcohol prohibition in the U.S. Prior to the enactment of state-wide or nationwide alcohol laws, each county determined its own alcohol policies. Thus, prohibition differentially treated counties depending on whether they were wet or dry prior to prohibition. I analyze three different prohibition episodes: the enactment of national prohibition, the imposition of prohibition at the state-level in the decades before national prohibition, and the removal of prohibition barriers in the 1930s. I consider several sample selection criteria, including utilizing data on county-level voting during prohibition referendums, to ensure that sample counties had consistent views on alcohol, in turn ensuring that changes are not driven by unobservable characteristics that also affect patenting behavior. Following national prohibition, previously wet counties had approximately 10% fewer patents per year. After prohibition at the state level, the estimated effect is even larger: previously wet counties have about 20% fewer patents per year relative to the dry counties. In both cases, the effect is largest in the first three years after the imposition of prohibition and rebounds thereafter. Consistent with the observed decrease in patenting being driven by a disruption of informal social interactions, the fraction of patents with multiple inventors falls, the diversity of patented ideas declines, and first-time inventors decrease their patenting more than serial inventors following prohibition. The patenting rate for men decreases more than that for women in previously wet counties. Removing prohibition appears to lead to a small increase in patenting, although the results are more mixed.

“Historical Changes in the Demographics of Inventors in the United States”
with Sarada and Nicolas Ziebarth
Who invents? This is a central question to understanding possible barriers to entry in the innovation process. To address it, we match the Annual Reports of the Commissioner of Patents from 1870 to 1940 to the corresponding U.S. Federal Population Censuses. This matching procedure provides a rich set of demographic information on a comprehensive set of inventors. We first document that patentees over this seventy year period are more likely to be older, white, male, and to be living in a state other than the one in which they were born. These patterns are very persistent over space and time. We then attempt to identify correlates of the demographics of patentees focusing on county-level economic and demographic characteristics. Beyond the most obvious, such as the fraction of a particular demographic group in that county, very little explains differences in the demographics of inventors across counties. We then examine two historical institutions that differentially affected particular demographic groups. For blacks, we consider historically blacks colleges and universities (HBCUs) and for women, state-level extension of the franchise. We find some evidence that HBCUs differentially increased black patenting rates while the extension of the franchise did not seem to have an effect for the representation of women among inventors.

“Comparing Historical Patent Datasets”
I compare the strengths and weaknesses of four historical patent datasets and compare the suitability of each for use in economic research. I show first that a number of historical sources exist that are nearly as complete as are data on contemporary patenting. Second, I describe in detail differences across the datasets in terms of patent and inventor information included, reliability of provided information, and potential sample selection issues. Third, I show that while there are some differences across datasets, overall they paint a remarkably consistent picture of invention in the historical United States.

References
Prof. Nicolas Ziebarth (Committee Chair)
Prof. Joel Mokyr
Prof. Joe Ferrie