There are many differences between Donald Trump and Kamala Harris. But one crucial similarity is that both have proposed terrible economic policies that have political appeal because of widespread voter ignorance.

Trump has proposed both large-scale tariff increases and mass deportation of undocumented immigrants. Harris’ plans include price controls and rent controls. All would cause great harm if enacted, but candidates advocate them because much of the public doesn’t understand the damage such policies bring with them.

Such misunderstandings are part of a broader problem of widespread voter ignorance about government and public policy.

Trump has proposed a 10 percent tariff on virtually all imported goods. This would predictably increase prices on a wide range of products, costing the average American family roughly $1,700 per year. The economic damage will increase if foreign governments retaliate against American exports, as they likely would. In addition, because many American industries rely on imported inputs, tariffs often destroy jobs and cause shortages. Trump’s first-term tariffs on aluminum and steel eliminated more jobs than they created, because these metals are inputs into many products.

The harmful effects of tariffs are the subject of a broad cross-ideological consensus among economists. Yet tariffs often get support from voters if presented as a way to save American jobs.

Trump’s mass deportation plans would cause similar harm. Undocumented immigrants are important contributors to many sectors of the economy. Mass deportation would predictably create disruption, increase prices and cause shortages. Deportations also destroy more American jobs than they create, because many U.S. citizens work in industries that depend on goods and services produced by undocumented workers. Such effects would be exacerbated by Trump’s plans to massively cut legal immigration, as well. Slashing immigration would also worsen the government’s already dire fiscal position. The Congressional Budget Office estimates that the increase in immigration since 2021 will reduce deficits by almost $1 trillion over the next decade.

As with free trade, there is broad agreement among economists on the beneficial economic effects of immigration. But many voters don’t understand that. Today, about half of Americans support mass deportation of undocumented migrants, though 70 percent also support creating a path to citizenship for them.

Meanwhile, Kamala Harris has tried to assuage voter concerns about high prices by promising to impose price controls to prevent “price gouging” in grocery sales. She has also endorsed President Biden’s plan to limit many housing rent increases to no more than 5 percent per year.

Price controls have a long history of causing shortages, including in the U.S. during the 1970s. When government artificially restricts prices, producers have less incentive to increase supplies in response to increasing demand. The same is true of rent control, which numerous studies consistently show exacerbates housing shortages.

Economists across the political spectrum agree here, too. Jason Furman, chair of Barack Obama’s Council of Economic Advisers, notes that “[r]ent control has been about as disgraced as any economic policy.” Nonetheless, polls indicate that both rent control and price controls more generally are often popular with voters. That is partly because a majority of the public wrongly believes that high prices are caused by “corporate greed.”

Businesses are indeed greedy for profits, but there is no good reason to believe corporations suddenly become more greedy during periods when prices rise. Corporate greed is a constant that cannot explain a variable like price increases.

Harris’s terrible proposals are less dangerous than Trump’s because nationwide price controls and rent control cannot occur without new legislation, which would be hard to pass. In contrast, much of Trump’s immigration and trade agenda could be enacted by executive action alone. Still, any idea endorsed by a major-party presidential candidate becomes thereby more likely to be enacted

Extensive support for these terrible policies is part of a broader pattern of widespread political ignorance. Decades’ worth of data show that most voters know very little about government and public policy. For example, surveys show only about one-third to a half of Americans can even name the three branches of government.

Political ignorance is perfectly rational for most voters. If your only reason for following politics is to be a better voter, that turns out to not be much of an incentive at all, because there is so little chance that your vote will actually make a difference to the outcome of an election (about 1 in 60 million in a presidential race). Such “rational ignorance” incentivizes politicians to promote harmful-but-popular policies.

The danger of ignorance isn’t just that it leads voters to choose the “wrong” candidate. It’s that it incentivizes both parties to promote harmful policies that cater to ignorance. Not all bad policies are caused by ignorance, but voter ignorance does facilitate some terrible policies that a better-informed electorate would reject.

Many hope that ignorance can be alleviated through education. But political knowledge levels have remained flat for decades, despite massive increases in education spending and educational attainment.

A more promising approach is to reduce the impact of ignorance by limiting and decentralizing government, thereby empowering people to make more decisions by “voting with their feet.” People can vote with their feet in the private sector (by choosing which products to buy or which civil society organizations to join) or by choosing what state or local government to live under in a federal system. If federal power is reduced, more issues will be left up to states, localities, and the private sector, and people will have a wider range of foot voting options.

Most people spend more time and effort acquiring information deciding what television to buy than deciding whom to vote for in a presidential election. That isn’t because the presidency is less important than your television. It’s because when people choose a television, they know the decision will make a difference. Extensive empirical and experimental evidence shows that foot voters seek out more information and use it better than ballot box voters.

Limiting government power also reduces the danger of voter ignorance by reducing the range of issues voters must consider. Currently, federal regulation reaches almost every type of human activity, from toilets to health care. A government with more limited powers would be easier for voters to keep track of.

At the very least, we must recognize political ignorance is a serious problem. If we continue neglecting it, we can expect more awful policies.