David Barrows, of Washington, DC, waves a flag with corporate logos and fake money during a rally against money in politics outside the Supreme Court October 8, 2013 in Washington, DC. On Tuesday, the Supreme Court heard oral arguments in McCutcheon v. Federal Election Committee, a first amendment case that will determine how much money an individual can contribute directly to political campaigns. (Photo by Chip Somodevilla/Getty Images)

Everyone thinks they know that money is important in American politics. But how important? The Supreme Court’s Gilded Age reasoning in McCutcheon v. FEC has inspired a flurry of commentary regarding the potential corrosive influence of campaign contributions; but that commentary largely ignores the broader question of how economic power shapes American politics and policy. For decades, most political scientists have sidestepped that question, because it has not seemed amenable to rigorous (meaning quantitative) scientific investigation. Qualitative studies of the political role of economic elites have mostly been relegated to the margins of the field. But now, political scientists are belatedly turning more systematic attention to the political impact of wealth, and their findings should reshape how we think about American democracy.

forthcoming article in Perspectives on Politics by (my former colleague) Martin Gilens and (my sometime collaborator) Benjamin Page marks a notable step in that process. Drawing on the same extensive evidence employed by Gilens in his landmark book “Affluence and Influence,” Gilens and Page analyze 1,779 policy outcomes over a period of more than 20 years. They conclude that “economic elites and organized groups representing business interests have substantial independent impacts on U.S. government policy, while mass-based interest groups and average citizens have little or no independent influence.”

Average citizens have “little or no independent influence” on the policy-making process? This must be an overstatement of Gilens’s and Page’s findings, no?

Alas, no. In their primary statistical analysis, the collective preferences of ordinary citizens had only a negligible estimated effect on policy outcomes, while the collective preferences of “economic elites” (roughly proxied by citizens at the 90th percentile of the income distribution) were 15 times as important. “Mass-based interest groups” mattered, too, but only about half as much as business interest groups — and the preferences of those public interest groups were only weakly correlated (.12) with the preferences of the public as measured in opinion surveys.

Gilens and Page frame their study as a test of four broad theories of American politics: “Majoritarian Electoral Democracy,” “Majoritarian Pluralism,” “Economic Elite Domination” and “Biased Pluralism.” “Majoritarian Electoral Democracy,” with its emphasis on public opinion, elections and representation, provides the theoretical backbone of most contemporary political science (including mine). The training of most graduate students (including mine) is primarily couched in that framework. But Gilens’s and Page’s work makes that look like a bad scientific bet, wishfully ignoring most of what actually drives American policy-making.

The theory of “Majoritarian Pluralism” emphasizes the role of organized interests, but assumes that most ordinary citizens will be fairly well represented in the tug-of-war among interest groups. It flourished in the mid-20th century, perhaps most notably in the work of David Truman and the early Robert Dahl, but has been much less prominent in recent years. The “Economic Elite Domination” and “Biased Pluralism” perspectives have been even less prominent in mainstream political science, although they have been deployed selectively by E. E. Schattschneider and Charles Lindblom, and in a more sustained fashion by G. William Domhoff, Thomas Ferguson and others.

Gilens’s and Page’s analysis suggests that we need a lot more research on “Economic Elite Domination” and “Biased Pluralism.” Stronger empirical tests of the political influence of economic elites will require better evidence regarding the political preferences and activities of wealthy Americans. Page, Jason Seawright  and I have made a small start in that direction with a pilot survey of millionaires in the Chicago area. In a paper presented at last week’s meeting of the Midwest Political Science Association, Page and Seawright began to explore a different approach, trying to learn about the political views of Forbes 400 billionaires by web-scraping their public comments and contribution records.

We also need narrower studies of specific channels of political influence. Joshua Kalla and David Broockman’s recent field experiment focusing on access to members of Congress provides an elegant example of that sort of work. A political organization contacted 191 congressional offices requesting meetings to discuss a pending bill. The organization’s members were randomly identified either as constituents or as campaign donors. Of the people identified as donors, 19 percent got meetings with the member of Congress or a top staffer, but only 5 percent of those identified as constituents (not as donors) got similar access. Clearly, as Kalla and Broockman observe, “individuals can command greater attention from influential policymakers by contributing to campaigns.” While that finding in itself does not tell us whether “greater attention” actually translates into substantial policy influence, it does shed clear light on one piece of the much broader process of “Economic Elite Domination” stunningly documented by Gilens and Page.