In a famous 2011 study, Michael I. Norton and Dan Ariely conducted a survey that asked a sample of Americans to build their ideal distribution of wealth. They also asked respondents to estimate how much wealth each quintile in America actually had. The results, depicted in the graph below (Adobe Flash required), were surprising:

The authors summarized the results:

First, a large nationally representative sample of Americans seems to prefer to live in a country more like Sweden than like the United States. Americans also construct ideal distributions that are far more equal than they estimated the United States to be—estimates which themselves were far more equal than the actual level of inequality. Second, there was much more consensus than disagreement across groups from different sides of the political spectrum about this desire for a more equal distribution of wealth, suggesting that Americans may possess a commonly held ‘‘normative’’ standard for the distribution of wealth despite the many disagreements about policies that affect that distribution, such as taxation and welfare (Kluegel & Smith, 1986).

Read Norton and Ariely's full study.