[1] A former economist for the Federal Reserve, Barker operates a real estate and finance company[2] and is an Iowa Republican Party official.

After completing graduate school Barker worked as an economist at the Federal Reserve Bank of New York, helping to develop an early warning system for failing banks and methods to detect racial discrimination in mortgage lending, as well as conducting analysis of the Basel Accord capital requirements.

[16][17] A paper analyzing the economics of the 1867 Alaska Purchase by the US from Russia argued that the financial returns to the federal government, tax revenue minus administrative costs, have been lower than alternative investments with similar risk.

[18][19] Barker is the author of Welcome to Free America,[20][21] a book set in 2057 as a guide to immigrants coming to the former United States after the collapse of government.

It describes a difficult period of transition, but eventually, private companies take over functions previously performed by governments, such as security, dispute resolution, production of money and infrastructure, and national defense.

[25] Barker's companies own over 2,000 apartments in the Midwestern United States, along with office buildings, self-storage facilities, and convenience stores.