Political Order and Inequality: Their Foundations and Their Consequences argues that geography, technology, and wars determined the formation of a ruling class, inequality, and institutional development, rather than the other way around. Institutions are not a cause but a consequence. This relatively short book covers an enormous amount of material. I have sympathy for the basic idea of the book, but in some parts I would have liked to see more detailed evidence, especially on the more recent history and the Industrial Revolution.

We survey and assess the literature on the positive and negative effects of ethnic diversity on economic policies and outcomes. Our focus is on communities of different size and organizational structure, such as countries, cities in developed countries, and villages and groups in developing countries. We also consider the endogenous formation of political jurisdictions and highlight several open issues in need of further research, in particular the endogenous formation of ethnic identity and the measurement of ethnic diversity.

We review the growing literature on the political economy of immigration. First, we discuss the effects of immigration on a wide range of political and social outcomes. The existing evidence suggests that immigrants often, but not always, trigger backlash, increasing support for anti-immigrant parties and lowering preferences for redistribution and diversity among natives. Next, we unpack the channels behind the political effects of immigration, distinguishing between economic and noneconomic forces. In examining the mechanisms, we highlight important mediating factors, such as misperceptions, the media, and the conditions under which intergroup contact occurs. We also outline promising avenues for future research.

A growing body of empirical work measuring different types of cultural traits has shown that culture matters for a variety of economic outcomes. This paper focuses on one specific aspect of the relevance of culture: its relationship to institutions. We review work with a theoretical, empirical, and historical bent to assess the presence of a two-way causal effect between culture and institutions.