Scott Sumer discusses taxes TheMoneyIllusion » Income: A meaningless, misleading, and pernicious concept. There have been responses by Bob Murphy, Richard Thaler and others all linked in his recent post titled Comment on Murphy and Thaler. I wish to draw attention to a more fundamental issues.
Firstly, we set the tax rates and plan expenditures accordingly. Why can't we do the reverse? I know the wording may not be clear so let me explain to the best of my abilities. Government sets tax rates, looks at collections, plans expenditure that (hopefully) results in more income and hence more taxes. This is a loop of sorts. However, I think we should go the reverse way, every year we should look at important, unavoidable, expenses and then deduce the tax rates from those. In the first case we tend to expand or contract government consumption (for the lack of better word - expenditure may not be appropriate) to fit the tax collections. In the second case we adjust the tax rates to fit with expenditure. It may lead to other issues related with fiscal deficits, productivity and development focus, and others. We will deal with them in a later post.
Second, taxes are less about being complicated right and more about being fair and easy. We have yet to discover a best first principles solution to tax calculation. Any mechanism we use ends up with unfair outcomes for certain portion of population. But if we stick to being fair, people should not have reason to complain. So I agree with you when you say that consumption is a better alternative.
Finally, taxes should not create distortions. Taxes are not means to guide the population and this, as such, should be considered as encroachment on civil liberties. Government has not business nudging people to have more babies, get more insurance, consume more, or invest in tax-havens etc. Alas, I am in a minority on this issue.