Who pays corporate income taxes? Just one thing’s for sure: it’s not corporations.

This is because, as Mitt Romney famously put it, “corporations are people, my friend.” They also sell to people, buy from people, and are owned by people. Yes, sometimes you have to dig through layers of other corporations, pension funds, foundations, and the like to get to these people. But they’re there somewhere, trying to avoid getting smacked by corporate taxes.

In econospeak, where the burden lands is called tax incidence. “The cardinal rule of incidence analysis,” UC Berkeley economist Alan Auerbach once said, “is you do not talk about incidence analysis.”  Actually, no, he didn’t say that — although this does seem to be the rule that most journalists, politicians, corporate executives, and even economists writing for mainstream audiences follow. What Auerbach did write in 2005 was that “the cardinal rule of incidence analysis” is “that only individuals can bear the burden of taxation and that all tax burdens should be traced back to individuals.”

In the case of the corporate income tax, as the Harvard Business School’s Mihir Desai put it in an interview I recently did with him and his HBS colleague Bill George, “that tax is going to be borne by shareholders, workers, or customers.”

For a long time it was thought the owners paid the tax. That belief can be traced largely to a classic 1962 theoretical analysis by economist Arnold Harberger, who concluded that owners of capital — not just a corporation’s shareholders but anybody who owned some bonds, a house, whatever — bore almost all the burden of corporate income taxes in the U.S.

Harberger saw this as a bad thing. By taking money away from capital owners, the corporate income tax was depressing investment and distorting the economy. But for those more concerned with the distributional effects of taxation, Harberger’s model at least showed the burden landing on people who were wealthier than average.

His theoretical model, however, assumed a closed economy, one in which capital couldn’t flee to other countries and consumers couldn’t buy foreign products. As the world’s economies became more intertwined in recent decades, economists — Harberger among them — began constructing open-economy models that showed workers bearing a larger share of the burden.

This makes intuitive sense. If a country allows free capital flows and free trade and has a corporate tax rate much higher than that of its neighbors, investors can choose to buy shares in companies elsewhere that face a lower tax, and corporate management can choose to move operations abroad. Consumers, meanwhile, can buy from foreign suppliers. By comparison, workers are pretty immobile. It’s hard for them to switch employers, let alone countries. So the tax lands on them, in the form of lower wages and/or skimpier benefits. And as those at the top of today’s corporate hierarchies seem to have done a pretty great job of keeping their paychecks from being adversely affected, the impact is presumably greatest on those farther down in the organization.

That’s the theory, at least. These models are, as Jennifer Gravelle of the Congressional Budget Office pointed out in a 2010 summary of recent theoretical work, extremely sensitive to how open an economy is and how sensitive people are to incentives. Tweak the assumptions just a little, and you can get a very different result.

So in the past few years there’s been a determined attempt to answer the question empirically, with a flurry of new regression studies that dig through data across countries, states, or even 13,000 German communities to suss out where businesses’ tax burden lands. Gravelle has a 2011 summary of this work, and her chief conclusions are that the results are all over the place and the most dramatic ones just aren’t credible. But most of these studies do show some significant chunk of the corporate tax burden landing on workers, which is perhaps not yet conclusive but is really interesting.

Most public discussions of corporate taxes in the U.S., however, still ignore the possibility that workers might actually be the ones bearing the burden. Perhaps this is because other public figures really want to avoid sounding like Mitt Romney. Perhaps tax incidence is just too difficult a concept for non-economists to get their heads around (although I’m not an economist and it seems pretty straightforward to me). Perhaps it’s that the evidence is still so mixed (although that hasn’t stopped economic arguments with far less empirical and theoretical backup from gaining currency in the political arena). Perhaps it’s that the corporate executives who lobby for lower tax rates don’t quite have the chutzpah to argue that this could result in higher wages. Or perhaps it’s just that, if corporations pay lower taxes, individuals have to pick up the slack. And even if you understand tax incidence perfectly well, a direct tax is still more noticeable than an indirect one.

We may as well rename this the Economics forum.