Last week, the United States government might as well have hung a sign on the front door of the Capitol that read, "Gone negotiating. We'll be back in…however long it takes."

In 2013, the U.S. government closed for 16 days. About 850,000 federal workers were furloughed and 6.6 million workdays lost. The shutdown affected private companies that worked with the government, too, and the U.S. economy took a hit.

The prospect of kicking off 2018 with a government shutdown didn't appear to concern investors too much. Barron's reported the Dow Jones Industrial, Standard & Poor's 500, and NASDAQ indices all finished the week higher.

The lack of response from investors isn't all that surprising. Geopolitical events – from the Brexit vote to the U.S. bombing Syria to the North Korean nuclear escalation – have had little lasting effect on markets. The president of a financial research firm told The New York Times, "geopolitical events may be widely feared, and there will often be a knee-jerk market reaction when they're unexpected, but seldom do they have a lasting impact. Underlying economic trends and monetary policy are far more important."

That has been the case with previous U.S. government shutdowns. However, Investor's Business Daily (IBD) wrote this time might be different:

"Government shutdowns always have been primarily over government spending, but this one will be mostly over an ideological divide on immigration, with budget issues playing a secondary role. That raises the risk that the partial government shutdown could be a long one and have more serious economic consequences than investors expect."

IBD suggested it wouldn't be long before the negative economic effects of dysfunctional government consume any economic gains delivered by tax reform. That may provide an incentive for our elected officials.