We spend billions just paying accountants to fool around wit millions of rules that most people do not understand. Sales tax is very simple. Rich people get out of paying taxes by doing inefficient things like tax shelters.

Now, the sales tax would need to be refunded for those in the basic income bracket, especially on food, housing, etc..

Remember that HN article about "We'll not incorporate in the US" by some Danish group? What needs to happen is to encourage businesses to run locally, and part of that is simplifying the entire structure to represent what the economy is closest to--consumption.