Quarterly Journal of Economics · 2021 · Henry S. Farber、Daniel Herbst、Ilyana Kuziemko、Suresh Naidu
中文摘要
过去100年间，美国收入不平等程度与工会密度呈反向变动。然而，事实证明，要超越这一总量关系开展研究十分困难，部分原因在于1973年以前关于工会会员身份的微观数据有限。我们开发了一项可追溯至1936年的工会会员微观数据新来源，主要采用盖洛普的调查数据（N≈980,000），以考察工会与不平等之间的长期关系。我们记录了工会会员人口构成的显著变化：在工会密度于20世纪中期达到峰值时，工会家庭的受教育程度远低于其他家庭，非白人比例也高得多；而在第二次世界大战前和当今，工会家庭在这些方面与非工会家庭更为相似。然而，尽管自1936年以来工会会员构成和工会密度发生了巨大变化，家庭层面的工会溢价仍相对稳定地保持在10至20个对数点之间。我们使用这些数据考察工会对收入不平等的影响。通过分布分解、时间序列回归、州—年份回归，以及一种基于1935年工会合法化和第二次世界大战时期战时劳工委员会的新工具变量策略，我们获得了一致证据，表明工会降低了不平等程度，并可解释20世纪30年代中期至40年代末不平等程度大幅下降中的相当大一部分。
Abstract
Abstract U.S. income inequality has varied inversely with union density over the past 100 years. But moving beyond this aggregate relationship has proven difficult, in part because of limited microdata on union membership prior to 1973. We develop a new source of microdata on union membership dating back to 1936, survey data primarily from Gallup (N ≈ 980,000), to examine the long-run relationship between unions and inequality. We document dramatic changes in the demographics of union members: when density was at its mid-century peak, union households were much less educated and more nonwhite than other households, whereas pre-World War II and today they are more similar to nonunion households on these dimensions. However, despite large changes in composition and density since 1936, the household union premium holds relatively steady between 10 and 20 log points. We use our data to examine the effect of unions on income inequality. Using distributional decompositions, time series regressions, state-year regressions, as well as a new instrumental-variable strategy based on the 1935 legalization of unions and the World War II–era War Labor Board, we find consistent evidence that unions reduce inequality, explaining a significant share of the dramatic fall in inequality between the mid-1930s and late 1940s.