Iowa Results Underscore Polling Industry Vulnerability

A disappointing night in Iowa for Donald Trump was just the latest setback to pollsters around the world.

The results in the state’s presidential caucuses on Monday showed Texas Senator Ted Cruz beating Trump in the Republican contest by 28 percent to 24 percent -- an outcome that was contrary to poll after poll that showed the billionaire winning.

In the Democratic contest, the virtual tie between Hillary Clinton and Bernie Sanders was uncomfortably close for both the former secretary of state and pollsters who showed her with a narrow but steady lead heading into the caucuses.

The results underscored the vulnerability of a polling industry that has been battered in recent months by inaccurate readings of public sentiment in votes from Israel, to Greece to Spain and the U.K. -- often by underestimating conservative turnout.

On Monday night, Iowans defied expectations by attending caucuses in unprecedented numbers to hand Cruz a momentum-shifting victory. Those misfires have raised doubts about the validity of polling at time of technological and social shifts even as political and business professionals increasingly rely on surveys and the data they collect.

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http://www.bloomberg.com/politics/articles/2016-02-02/iowa-s-other-losers-polls-that-showed-trump-ahead-before-caucus