My dissertation examines the following question: Can multi-ethnic states purposefully engineer the identities of their citizens to shape important outcomes? Specifically, I examine whether public policy can be used to change the salience and behavioral manifestations of ethnic and civic identities in theoretically and practically important ways. This is relevant, I argue, because the role of public policy is an important but often neglected piece of the puzzle of why there is so much geographic and temporal variation in the effects of ethnic diversity.

The basic premise that public policy can impact identities is not widely disputed. There is, however, little consensus about which policies have which effects. In addition, few comparative studies have sought to produce insights into the potential magnitudes, limits, time frame, and mechanisms of policy-induced identity change. This is due in large part to two fundamental methodological challenges. The first is that it is difficult to isolate the causal effect of policies, and the second is that it is difficult to accurately measure the salience of ethnic and civic identities.

My dissertation has three related objectives, all geared towards providing insights into how policy affects outcomes in ethnically heterogeneous environments. The first is to isolate the effect of policies from other structural factors like relative group size. I achieve this through a causal identification strategy based on measuring the effects of exogenous variation in treatment intensities of key policies, and to a lesser extent, through careful case matching. The second objective is to develop a set of theoretically meaningful and unbiased measures of ethnic and civic identities. I achieve this through several innovative approaches to measurement, including vignettes and survey experiments. The third objective is to develop a theoretical framework to explain how policy can change the divisive potential of ethnic diversity. Specifically, I argue that the presence of strong civic identities, which can be bolstered through concerted policy efforts, have the capacity to bridge ethnic divisions.

I find clear evidence that policy can substantially alter the divisive potential of ethnic heterogeneity independently of structural factors like relative group size. These findings are based on an extensive NSF-funded survey conducted in Malaysia and Singapore, the first of its kind in those countries to use experimental methods to address fundamental questions of identity salience and its determinants. I anticipate that the resulting dataset will continue to provide valuable insights into ethnic and civic identities beyond the scope of my dissertation.

The study of ethnic politics has largely moved beyond the debate over whether to conceptualize ethnicity in generalized primordial or constructivist terms, instead shifting focus to the subtle ways that ethnic diversity structures political dynamics. This dissertation contributes to that evolution by providing important insights into how the state can affect the microfoundations of ethnic politics through concerted policy efforts.