When in office, former President Clinton proposed a very simple flat personal income tax system for the Federal government.

FORBES: A Simple Federal Flat Personal Income Tax System

He has advocated a simple two-rate personal income tax system, under which individual taxpayers could fill out their returns on a single sheet of paper.

FORBES: What Next?

And in this case, delivering an individual worker credit through the payroll tax system muddies the waters between personal income taxes and taxes paid to support Social Security.

FORBES: Federal Payroll Tax Cut in 2011--Roots for an Individual Worker Credit?