Researchers have long tried to isolate the impact of right-to-work to measure its influence on a host of possible outcomes. The great challenge is teasing out the effects of right-to-work laws from other confounding factors, which could include everything from a state’s climate and topography to citizens’ attitudes toward labor unions, the state’s economic condition prior to its adoption of a right-to-work law and other state-specific public policies.
In his 1998 paper titled, “The Effect of State Policies on the Location of Manufacturing: Evidence from State Borders,” Thomas J. Holmes explored changes in manufacturing employment along state borders where one county operates with a right-to-work law is next door to another one that does not.[9]
Holmes used right-to-work laws to label states either pro- or anti-business. In other words, right-to-work laws served as a proxy for pro-business policies. He found that “on average, there is a large, abrupt increase in manufacturing activity when one crosses a state border from an anti-business state into a probusiness state.”[10] Specifically, Holmes showed that manufacturing employment as a percentage of total employed increased by one-third, on average, in border counties in states with right-to-work laws.[11]
The Holmes method acts as a de facto control on the other economic phenomena that might influence manufacturing employment, because there is little to distinguish bordering counties in different states other than state-level policies. There is little difference between the two entities when it comes to factors like geography, regional market performance, weather, access to trained workers, etc. Scholars have repeatedly validated Holmes’ approach — it has been cited more than 1,000 times according to Google Scholar, one measure of the scholarship’s influence.
It is this basic methodology and modeling effort that we began an attempt to measure impacts that right-to-work laws have on employment in 18 industry sectors across the country, most notably in manufacturing and in other industries where unions are most prevalent, and to Michigan and Indiana’s right-to-work laws specifically.