Immigration and product diversity
研究了移民对消费选择多样性的影响，发现移民与大型零售商增加、独立零售店减少相关，但增加了餐馆的种族多样性，部分源于移民在生产民族商品上的比较优势。
We study the effects of immigration on the diversity of consumption choices. Data from California in the 1990s indicate that immigration is associated with fewer stand-alone retail stores and a greater number of large and in particular big-box retailers—evidence that likely contradicts a diversity-enhancing effect of immigration. In contrast, focusing on the restaurant sector for which we can better identify the types of products consumed by customers, we find that immigration is associated with increased ethnic diversity of restaurants. This latter effect appears to come in part from the comparative advantage of immigrants in the production of ethnic goods.