Racial Mix and Industrial Productivity
研究了美国制造业中劳动力种族构成与行业生产率的关系，发现黑人占比与生产率正相关，挑战了传统理论。
The relationship between the racial composition of the work force in an industrial category and that industry's level of productivity is explored. The logic of the major theories of labor-force behavior implies that a large minority labor-force presence will be negatively correlated with an industry's level of productivity because of the relatively weak attachment to the work force of such groups as blacks and women. After exploring information about the manufacturing industries in the United States in the early 1960s and early 1970s, we find no evidence to support this implication. If anything, an industrial category's level of productivity is positively related to the percent black in that industry's labor force, once other relevant characteristics are controlled. These preliminary findings deserve further theoretical and empirical specification.