From the Becker-Posner blog:
The Occupy Wall Street movement has not expressed clear goals, but it does want higher taxes on the “rich”. President Obama agreed in his State of the Union address, and proposed that the rich-in his case, anyone with an annual income of at least $1 million- pay no less than 30% of their income in federal taxes. Others have proposed to add annual taxes on household wealth, in addition to taxes on income. The fact is that Obama’s tax goal is already being met by the complicated American tax code, while even a small wealth tax would discourage savings and create other problems.
According to a 2010 study by the Congressional Budget Office, the effective federal tax rate on the top 1 percent of households has already been about 30%. This might seem to be a misprint since very wealthy persons like Warren Buffet and Mitt Romney report that they pay only about 15% of their income in taxes. However, much of their incomes come from investments that are first taxed at the corporate tax rate of 35%, and then the after-corporate tax income is taxed again when paid out as corporate dividends, or when capital gains are realized.