One thing that is often ignored when considering a progressive income tax is that years of income are often sacrificed in order to achieve higher earnings. Cons

One thing that is often ignored when considering a progressive income tax is that years of income are often sacrificed in order to achieve higher earnings. Consider an entrepreneur who earns <$30,000 for for 5+ years while re-investing in a breakthrough technology, or a doctor who spends 10+ years studying and living on a minimal income who one year earn $250,000+ and fall into the highest tax bracket. Those individuals have basically concentrated all of their earnings into a shorter time period, at (in the entrepreneur's case) significant personal risk/expense. This can make the net lifetime earnings of these supposedly 'rich' individuals actually less, and taxed at a higher rate, than those who don't ever achieve this level of income.