I learn a lot from reading Brad DeLong or the economically-inclined folks at Crooked Timber, but I get special enjoyment from Marginal Revolution. (I'm actually not being sarcastic for once, in case it's unclear.) Much like training in physics affects they way you view the physical world, training in economics affects the way you view -- well, almost everything. All of life becomes an exercise in maximizing returns and minimizing costs, subject to constraints. Consider for example the Tennis Ball Problem.
How many tennis balls should you play with? Let's say you had many, many balls and you could open the cans for free and never run out. Opening a new can every four points (four balls fit in a can) would lead to a massive clean-up and carry problem at the end. Furthermore how much help is it having more balls? Once they hit the net you still have to deal with getting another ball into play. In other words, the real trick is to manage your stock well (read: aim for good volleys), not to just to speed up the flow of balls into the court. Just one ball is not efficient, because when it falls out of play it is probably far from you. The greater the number of balls, the more likely at least one will be close. Many problems in life, including those of dating, the number of children you should have, and optimal inventory management, resemble the tennis ball problem. I do not know how to solve the tennis ball problem, but I feel that twelve balls is too many.
Those last two sentences just about sum it up, don't they?
