Photo by Flickr user Thomas Galvez , used under a CC license.

It's no secret that in many respects, politics is a game for the affluent. The more money you have, the more likely you are to pay attention to politics, to vote, or to donate money or time to a political cause. Money also buys you access to the politicians of your choice.

But it's been difficult to precisely quantify the political activity of the super-rich. For starters, there just aren't that many of them. Much of our information about political behavior comes from surveys. If the average survey sample contains 1,000 respondents, by definition only about 10 of them will be part of the richest 1 percent -- not nearly enough to draw any conclusions.

Now a new study out from Fay Lomax Cook, Benjamin Page and Rachel Moskowitz at Northwestern University aims to quantify the political behavior of the super-rich to see how they act compared to everyone else. Finding data for that "everyone else" was easy -- a 2009 Pew Research Center survey provided detailed information on the civic engagement of all the poor schlubs making up to the $150,000 range.

To get at political attitudes of the rich, they interviewed 83 of the wealthiest households in Chicago, who make up a representative subsample of the nation's 1 percenters. These households had an average wealth of $14,000,000. Several owned considerably more than that.

The authors recognize that this is a smallish sample, and a geographically-limited one at that. There may or may not be significant differences between the wealthy in Chicago and the wealthy everywhere else. But, "these data on top wealth holders are the best available and are likely to remain so," they note, "unless and until someone can conduct a national study a very major undertaking."

"On the other hand," they write, "the Chicago metropolitan area has some advantages as a survey locale. In political terms, the Chicagoarea wealthy may fall somewhere in between wealthy people in such diverse places as New York City, Dallas, and Silicon Valley."

Caveats aside, let's take a look at the numbers.

The chart shows participation in various political activities among income groups represented in the Pew survey, as well as participation among the wealthy Chicago households. "By several measures, wealthy Americans participate politically at two or three times the rate of members of the general public as a whole," Cook and her colleagues write.

Most strikingly, 99 percent of the wealthy said they voted in the 2008 election, compared to self-reported participation rates in the low-70 percent range among low-income Americans (since we know overall voter turnout was in the 62 percent range that year, it's likely that people overstated their voting in the surveys). Compared to Americans in the lowest income group, the wealthy are three times more likely to talk about politics, four times more likely to attend political events, and six times more likely to donate to political campaigns.

Particularly surprising are the consistent differences between the merely affluent -- the rabble making $150k+ per year -- and the truly wealthy. You might expect the effects of money on political participation to level off after a certain threshold, but these numbers suggest that more money = more politics, all the way to the top.

One of the implications of the study is that our representative democracy is not as representative as it could be. Relative to other income groups, the wealthy are overrepresented in the political process simply because they're more likely to participate in it. This means that political debates -- and political outcomes -- are much more reflective of the interests of a wealthy minority than they are of the middling majority.

The answer to this imbalance isn't to decrease political engagement among the wealthy, but rather to increase it among other income groups. This seems like a no-brainer, which makes contemporary Republican attempts to limit the size and diversity of the electorate a particularly puzzling spectacle -- especially when you consider that 'voter fraud', the alleged raison d'etre behind the new voting restrictions -- is essentially nonexistent.