Identity politics plays a central role in contemporary political divisions—shaping voting behavior, social preferences, and conflict. Notably, these patterns often contradict material self-interest. For instance, poor white voters in the U.S. often oppose redistribution—despite being its likely beneficiaries (Alesina and Glaeser, 2004). This raises two fundamental questions: What role do economic incentives play in shaping identity politics and racial hate? And, if not economics, what forces drive these behaviors?
Slaveocracy: Elite Capture and the Support for Slavery
To address these questions, we study slavery—arguably the most foundational exclusionary institution in U.S. history and one that continues to shape political identity today (Acharya et al., 2016). While economic historians have thoroughly documented the material incentives that made slavery profitable for slaveowners (Fogel, 1989; Wright, 2006; Olmstead and Rhode, 2010), a major puzzle remains: why did the broader white population—most of whom did not own slaves—so staunchly support the institution? Before the Civil War (1861–1865), 75% of Southern white men were non-slaveholders, yet they defended a system that undermined regional development, depressed investment in human capital, slowed technological progress, and concentrated wealth in the hands of a small elite (Sokoloff and Engerman, 2000; Nunn, 2008; Wright, 2022; Hornbeck and Logan, 2023). More generally, why do extractive institutions that benefit only a narrow elite persist, even under democratic rule?
In new research with Federico Masera, we study how elite economic incentives shaped broader political behavior. We focus on slavery’s profitability—driven largely by cotton—and model how changes in agricultural comparative advantage during Westward Expansion altered elite interests. As the population moved westward, the colonization of new land shifted counties’ comparative advantages in the use of slave labor. Figure 1 shows the geographic variation of changes in comparative advantage between 1810 and 1860 along with the Westward Expansion. Exploiting this variation, we estimate how changes in the returns from slavery translated into political support in Congress. We find a large effect of slave profitability on support for the institution. Interestingly, the effects are too large to be explained by changes in elite voting behavior alone. On the contrary, only about 30% of the change in pro-slavery votes can be attributed to slaveholders. This suggests that economic motives extended beyond the planter class and motivates our analysis of the mechanisms that allowed the planter elite to secure the support of the broader white population.
Figure 1. Change of Comparative Advantage over Time.