Those studies have always struck me as ironic since your average liberal has no knowledge of things like the laws of supply and demand and diminishing marginal utility.
Now here's a study to actually prove that........
Who is better informed about the policy choices facing the country—liberals, conservatives or libertarians? According to a Zogby International survey that I write about in the May issue of Econ Journal Watch, the answer is unequivocal: The left flunks Econ 101.
Zogby researcher Zeljka Buturovic and I considered the 4,835 respondents' (all American adults) answers to eight survey questions about basic economics. We also asked the respondents about their political leanings: progressive/very liberal; liberal; moderate; conservative; very conservative; and libertarian.
Rather than focusing on whether respondents answered a question correctly, we instead looked at whether they answered incorrectly. A response was counted as incorrect only if it was flatly unenlightened.
Consider one of the economic propositions in the December 2008 poll: "Restrictions on housing development make housing less affordable." People were asked if they: 1) strongly agree; 2) somewhat agree; 3) somewhat disagree; 4) strongly disagree; 5) are not sure.
Basic economics acknowledges that whatever redeeming features a restriction may have, it increases the cost of production and exchange, making goods and services less affordable. There may be exceptions to the general case, but they would be atypical.
Therefore, we counted as incorrect responses of "somewhat disagree" and "strongly disagree." This treatment gives leeway for those who think the question is ambiguous or half right and half wrong. They would likely answer "not sure," which we do not count as incorrect.
In this case, percentage of conservatives answering incorrectly was 22.3%, very conservatives 17.6% and libertarians 15.7%. But the percentage of progressive/very liberals answering incorrectly was 67.6% and liberals 60.1%. The pattern was not an anomaly.