Your simplistic solution will not work - Barack Hussein Obama

Some of us learned this in the 1960s and 1970s.  One of my favorite papers is:

Jay W. Forrester, "Counterintuitive Behavior of Social Systems", 
Technology Review, Vol. 73, No. 3, Jan. 1971, pp. 52-68.

It's first two paragraphs are:

"This paper addresses several issues of broad concern in the United States: population trends; the quality of urban life; national policy for urban growth; and the unexpected, ineffective, or detrimental results often generated by government programs in these areas.

"The nation exhibits a growing sense of futility as it repeatedly attacks deficiencies in our social system while the symptoms continue to worsen. Legislation is debated and passed with great promise and hope. But many programs prove to be ineffective. Results often seem unrelated to those expected when the programs were planned. At times programs cause exactly the reverse of desired results."

The lessons which should be learned from this include:

1. The Road to Hell is paved with Good Intentions
2. Donald J. Trump's proposals should be subjected to simulation by currently available decision support tools.

An updated version of the paper is available at http://static.clexchange.org/ftp/documents/system-dynamics/SD1991-04SDandLessonsof35Years.pdf