The Park Place Economist


Job polarization has changed the US labor market significantly over the past half century. There has been a significant growth in the share of high-skill jobs, while middle-skill jobs have declined rapidly. Previous research has identified skill-biased technological change (SBTC) and liberalized trade as the driving forces behind job polarization. However, all recent research has been focused around either the overall labor market or a small subset of jobs that represent the overall labor market. This paper instead looks at one sector in particular, manufacturing, to see how polarization has changed it over time. This sector is considered to be solidly “middle-skill,” as working in manufacturing typically means that a worker completes routine tasks. Automobile manufacturing is an industry within manufacturing that is frequently brought up in discussions about the decline in the manufacturing sector as a whole and is also subject to analysis in this paper. I use data from the American Community Survey and the Dictionary of Occupational Titles to determine whether job polarization can be observed in these two groups through changes in the shares of different skill-levels between 1980 and a pooled sample of 2013-2017 and whether polarization can be observed in changing wages for different skill levels between 2005 and 2015. I find that although the share of middle-skill workers has decreased in overall manufacturing, the same cannot be said for automobile manufacturing. Additionally, I find that wages had indeed polarized between 2005 and 2015.