Not that many people vote in midterm elections. While 57.5 percent of eligible voters cast ballots in the 2012 presidential race, a mere 41.9 percent did in 2014, according to data from the Census Bureau. Midterm turnout isn’t just low, though. It’s falling. It tumbled from 47.8 percent in 2006 to 45.5 percent in 2010 before falling yet further to 41.9 percent in 2014.

This has a real impact on who we elect. Americans who vote are different from those who don’t. Voters are older, richer, and whiter than nonvoters, in part because Americans lack a constitutional right to vote and the various restrictions on voting tend to disproportionately impact the less privileged. In 2014, turnout among those ages 18 to 24 with family incomes below $30,000 was 12 percent. Turnout among those older than 65 and making more than $150,000 was 65 percent. The result is policy that is biased in favor of the affluent. As I argue in a new report, "Why Voting Matters," higher turnout would transform American politics by giving poor, young, and nonwhite citizens more sway.

Nonvoters and voters disagree on economic issues

People’s opinions on policy issues vary considerably based on age, income, and race, so it’s perhaps unsurprising that their opinions diverge quite a bit from those of voters. The chart below, created with data from the American National Election Studies 2012 survey, shows net support (percent against subtracted from percent in favor) for various economic policies. It shows that voters and nonvoters have dramatically different preferences: Nonvoters support more services, a job guarantee, and government action to reduce inequality, while voters oppose these policies. While both voters and nonvoters support boosting spending on the poor, nonvoters are far more favorable to it.

But would boosting turnout actually change policy? We have reason to think so. Research suggests that voters are indeed better represented than nonvoters, but the historical and international record lend support to the thesis as well.

More voting has traditionally led to liberal spending policies

Numerous scholars have studied the gradual expansion of the franchise internationally and discovered that increased participation boosted the size and scope of the welfare state. A study of 12 Western European countries over the period of 1830 to 1938 finds, "The gradual lifting of socio-economic restrictions on the voting franchise contributed to growth in government spending." The effect hasn’t gone away in recent years. A study of the period from 1960 to 1982 concludes that higher turnout boosts welfare spending, even after controlling for political and environmental factors.

The expansion of the franchise to women is also instructive. As women gained access to the franchise within the United States, state government spending increased dramatically (see chart below). Indeed, the enfranchisement of women boosted spending on public health so significantly that it saved an estimated 20,000 children each year.

Later, the civil rights movement mobilized the Southern black electorate, which led to more liberal voting patterns among Southern Democrats and a boost in government spending going to black communities. The elimination of poll taxes and the subsequent mobilization of poor voters also lead to an increase in welfare spending.

Low voting rates help explain why the US has fewer benefits than other rich countries

There are many reasons the United States doesn’t have an expansive welfare state, like nearly every other high-income country. However, one important part is low voter turnout. The scatterplot below, created by Lane Kenworthy and Jonas Pontusson, shows the dramatic divergence between the United States and other countries in terms of both voter turnout and government spending.

In his book Macroeconomic Policies of Developed Democracies, Robert Franzese examines how inequality, turnout, and redistribution work together. The chart below shows his findings. It’s a bit complicated, but it’s very important. On the vertical axis Franzese has charted how much governments redistribute in response to an increase in income inequality. The horizontal axis shows years since inequality increased, and the lines are countries with different levels of turnout. As you can see, countries with low turnout, such as the United States (the x’s) and Switzerland (white diamond) don’t respond dramatically to increases in inequality (thus the lower lines, suggesting lower redistribution after an increase in inequality). On the other hand, countries like Australia (dark diamond) and Italy (white star) respond quickly and dramatically to increases in inequality (thus, the higher lines).

The international evidence therefore provides strong reason to believe that bolstering turnout would indeed lead to more redistribution, and thus be a possible palliative to rising inequality.

Politicians have little reason to listen to the poor

Already in America, the wealthy are more likely to donate to politicians, work on political campaigns, and be in regular contact with elected officials. In addition, politicians are far wealthier than ordinary citizens. These biases already conspire against the interests of poor people.

But deep differences in turnout based on income, age, and race only serve to further reduce the poor’s say. In the status quo, politicians don’t have incentives to listen to ordinary Americans, because it won’t cost them anything. That won’t change until turnout among nonwhite and poor voters increases. There are a number of ways that government can encourage voting: by fixing the Voting Rights Act, by enacting automatic voter registration, by repealing voter ID laws. All would give the poor more voice, and give policies they support a better chance of passage.

Correction: An earlier version of this article incorrectly stated the turnout rates for those ages 18 to 24 with family incomes below $30,000 and those older than 65 and with family incomes above $150,000.