It's a common refrain that the tax code is excessively complicated. One obvious and frequently deplored reason is that politicians like to use the tax code to provide favors for special interests in exchange for contributions and support. But another cause deserves equal scrutiny, and that is the belief that people should be steered toward particular choices or behaviors and away from others. Aside from leading to a Swiss cheese-style tax code, this sort of paternalism often backfires, creating more problems than it solves. It must stop.