Firm racial segregation and affirmative action in the highway construction industry
研究发现加州高速公路建设企业存在种族隔离现象，尤其是黑人和亚裔企业集中在同种族居民多的区域；平权行动削弱后，这些区域的企业数量相对减少，表明平权政策影响少数族裔企业的生存。
In this paper I document that highway construction firms in California, particularly those owned by blacks and Asians, exhibit considerable racial segregation in that they are disproportionately located in zip codes with the greatest concentration of own-race residents. I find that segregated firms serve a larger market than minority-owned firms that are not segregated and that this effect is concentrated in black-owned firms. I next exploit the segregation of firms to examine the effect of affirmative action on the success of minority-owned firms. Following the significant curtailment of affirmative action in California due to a direct statewide ballot initiative, the number of highway construction establishments located in zip codes with the highest concentrations of black and Asian residents fell relative to the rest of the state, even conditional on the number of non-construction establishments. This suggests that affirmative action policies may play a role in the net survival rates of minority-owned firms.