I would suspect that the reason that the Obama’s effective tax rate is 33% instead of the 16% that is more typical for a very wealthy American is that as President his tax return will be made public and inspected closely. Thus Obama does not use all the questionable loopholes that the very wealthy pay their accountants to find.

Nicholas Brown, a commentor responding to Planet Money’s audience-sourced scrutiny of the Obamas tax return in a tax-day post, Obamas Made $5.5 Million Last Year, Paid $1.8 Million In Taxes. The blog post explained the audience question:

I was going to call an accountant and ask if she saw any interesting details in the returns. Then I decided it would be ridiculous to try to get an accountant on the phone at 4:45 p.m. on April 15th. So I’ll put the question to the tax mavens among our readers.