Now, if you go back even further you can find that income tax rates in the late 1920s were temporarily similar to those of today. So, essentially, we currently have tax rates at their lowest levels (save a few of the Bush 1 years) since before the Great Depression. In the 1920s, recall, we didn't have Medicare, Medicaid, Social Security, unemployment insurance, etc. So, if you hear someone complaining that our income tax rates are holding back small businesses or entrepreneurs, ask yourself: compared to when?
And, yes, you could argue and say that it's not just the top marginal rate that matters, but also the income at which the rate goes into effect. The fact that effect tax rates on the rich are at near all time lows, for example, is noted in this Poltifact piece: "for those in the top 0.01 percent of the income distribution, the effective tax rate was 71.4 percent in 1960, 74.6 percent in 1970, 59.3 percent in 1980, 35.4 percent in 1990, 40.8 percent in 2000 and 34.7 percent in 2004. If lower taxes did actually deliver economic growth, then our country should be booming! Also, is it any wonder we're having trouble paying for our social safety net with these kind of declining contributions?