I have often noted (see here too) that we generally suck at math, to our great detriment. I have also noted that we are especially poor at dealing with probabilities. If a weather forecaster says that there is an 80 percent chance of rain and it remains sunny, instead of waiting to see if, in the aggregate, it rains 80 percent of the times when his or her forecast called for an 80 percent chance of rain, we race to conclude — perhaps based upon that single instance — that the forecaster isn’t any good. Data trumps our lyin’ eyes, but we don’t routinely see it (and even deny its efficacy).
Further evidence – as if it were needed – in support of my thesis has been offered this week in the reaction to Nate Silver’s projection that Republicans have a very real chance of gaining control of the Senate later this year. This forecast (“a Republican gain of six seats, plus or minus five”) is hardy earth-shattering to anybody who has been paying attention. The configuration of seats up for election favors Republicans and the Democratic President’s approval ratings are dreadful. There isn’t much reason to expect an upswing in Democratic support either, even though (obviously) almost anything could happen over the next few months. Dealing with probabilities necessarily means being wrong sometimes.