There is a widespread belief among politicians, pundits, and the media that turnout matters in American elections. That is perhaps why President Obama recently endorsed the idea of mandatory voting. Yet, as widely held as this conventional wisdom may be, it gets little empirical support. Political scientists who have tried to investigate these claims empirically have generally found no consistent link between a skewed electorate and biased outcomes. As John Sides noted, study after study has shown that increasing or decreasing turnout would not ultimately change who wins and who loses.

But in one very important way, these studies are all missing something. They all focus on national elections for Congress or the Presidency, which are obviously important elections that we should pay attention to. But these are not the elections that we should look at if we want to know how much turnout matters. We should be looking at local elections.

Focusing on national elections minimizes the possibility of finding bias for two reasons. First, simple logic dictates that the possible bias produced by uneven turnout decreases as overall turnout levels increase. If almost everybody turns out, there can be very little bias. If, however, only a small fraction of the entire electorate turns out, bias can be severe. So we should study subnational elections — from statewide races to school board contests — where turnout can often drop below 10 percent of the voting-age population.

The second reason why turnout should matter more outside of national elections is that particular groups can be small minorities and insignificant at the national level but a large fraction of the population in some localities.

Asian Americans, for example, make up 5 percent of the total national population.  Whether they vote is almost immaterial to the outcomes of presidential elections. However, Asian Americans make up the majority of the population in Hawaii and a third of the population of San Francisco and San Jose. Whether groups like Asian Americans vote could very much affect elections in these places.

My research has examined the effects of turnout in local contests. In America’s Uneven Democracy I focused specifically on the impact of turnout on the representation of racial and ethnic minorities. The book shows that who wins and who loses in local democracy is shaped in no small part by who votes.

If the participation of each of America’s racial and ethnic groups were even, we would likely see outcomes that diverged sharply from what we see today. Change would perhaps be most dramatic in mayoral elections where up to a third of the elections I examined could have ended with a different winner had turnout been even across racial and ethnic groups.

But city council representation could also be transformed by expanded turnout. Cities with higher levels of turnout have much greater minority representation on city councils, all else equal. If we could increase local turnout, we might eliminate almost one quarter of the underrepresentation of Latinos and Asian Americans on city councils across the country.

Finally, I find that turnout is closely linked to the policies that governments pursue. Municipalities with higher turnout spend more on welfare and other redistributive programs favored by minorities and less on areas favored by more advantaged white interests.

In short, limited and uneven participation has helped to restrict the number of minorities in local office, which in turn affects government spending priorities. As a result, Latinos, Asian Americans, and African Americans regularly end up on the losing side because their voices are more muted than they could be.

How could this situation be addressed? Of course, mandatory voting is unlikely to be enacted. But there is a simpler and more attainable solution. I have found that one small reform – changing the dates of local elections to coincide with the dates of state and national elections – could increase turnout by roughly 30 percentage points. Because the shift to on-cycle elections would save cities money and would usually only require the approval of the local city council, it could be widely and relatively easily implemented.

Low and uneven turnout is not the only problem in American democracy. It may not even be the biggest problem. But it is a problem and it should not be ignored – especially given that there are readily available solutions.

Zoltan L. Hajnal is a professor of political science at the University of California, San Diego.