Fascinating:

The most important year in a boy’s baseball life is indeed age 8. If a team wins a World Series when a boy is 8, it increases the probability that he will support the team as an adult by about 8 percent. Remember, this is independent of how good the team was every other year of this guy’s life. Things start falling off pretty fast after the age of about 14. A championship when a man is 20 is only one-eighth as likely to create an adult fan as a championship when a boy is 8. Just winning games also matters, with a similar age pattern. But the data shows that there seems to be something really special about winning championships.

They might be Giants:

In 2012, the San Francisco Giants won 94 games and the World Series. That year, they made $129 million in gate revenues. The traditional analysis would say, relative to a .500 season, that the Giants’ 2012 run made them about $33 million in gate revenues — about $18 million from increased attendance during the pennant race and $15 million from more excited fans the following year.

But my model suggests that among 5- to 15-year-olds in 2012, 5 percent more fans will root for the Giants for the rest of their lives. Assume spending on baseball increases at roughly the rate of interest. And assume that these fans spend about as much as the average fan. The Giants can expect about $33 million, in net present value, from here on out, from their 2012 season, just from the boys they won over.

A championship season, in other words, is at least twice as valuable as we previously thought.

Loyalty is susceptible to when you were born:

The explosion of big data sets should lead to the rapid development of precise insights into how events at every year of our childhood affect how we think as adults. We can learn a lot about the formation of tastes and preferences, both trivial and fundamental. Do you like Coke or Pepsi as an adult? Cheerios or Raisin Bran? Obama or Romney? All these answers can now be compared to things that happened to us as children. Already, some scholars have found fascinating long-term effects of events that happened while we were young on our political and economic outlooks.

The economists Ebonya Washington of Yale University and Sendhil Mullainathan of Harvard University found that if you are just old enough to vote in a presidential election, you will be more likely years later to be a partisan of the party you voted for than if you were slightly too young to vote in that election. Another pair of economists, Ulrike Malmendier, at the University of California, Berkeley, and Stefan Nagel, at the University of Michigan, found that if you grew up in bad economic times, you are more risk averse as an adult.