A perennial and crucial question — one intimately tied to the national security interests of the United States — is how to design political institutions that can mitigate ethnic conflict. This issue was front-and-center when the United States worked to establish new Iraqi political institutions after the overthrow of Saddam Hussein (see, for example, here). The conundrum is this: can you design political institutions that enable ethnic groups to be or at least feel represented in government, while not simultaneously exacerbating ethnic divisions?
What is the best electoral law for stable democratic government in ethnically divided societies? Constitutional engineers have long debated this question, typically focusing on the relative merits of proportional electoral laws (“PR”), which provide representation to parties in proportion to the number of votes that parties receive. It has been widely believed that PR politicizes ethnicity, with some arguing that this is a good thing (because each ethnic group will have its own party, encouraging them to participate non-violently in the democratic process) and some arguing it is bad (because the goal should be to depoliticize ethnicity, encouraging voters to focus on other factors, such as economic class). This debate, however, has been plagued by the absence of facts: we have not had the technology to test the effect of electoral laws on the politicization of ethnicity.
This research develops measures that can be used to assess the degree to which ethnicity is politicized in the electoral politics of a country. The measures focus on the connection between ethnic identity and voting behavior. The tighter this connection, the greater the degree of ethnic politicization. Applying the measure to a wide range of countries, the study demonstrates that in fact PR is associated with lower levels of politicization. This finding has important implications for constitutional design in divided societies and provides fact-based evidence supporting advocates for PR.
It also helps us to understand racial politics in the US. If Hispanic Americans want to be influential as a group within the plurality system of the US, they must vote cohesively. If the US operated under proportional representation, then different parties would compete for the Hispanic vote thereby diminishing the salience of race in elections.