Earl Weaver would have agreed with me. He had ten Laws, the seventh of which was "It's easier to find four good starters than to find five." Yet most baseball teams insist on five starters, with me usually cringing every time the Red Sox send out their fifth. ("Does this have anything to do with Jason Johnson giving up a leadoff triple to start the game against the Yankees today, Professor?" You know me too well.)

Likewise, proposals to limit school class sizes assumes that the supply of good teachers is practically infinitely elastic. As Frank Stephenson points out, that ain't necessarily so.

Proposals at both the state and federal levels have called for class-size reductions in an effort to boost student performance. Typically, such proposals have implicitly assumed that teacher quality will remain constant when hundreds or thousands of additional teachers are hired to lead the smaller classes. This assumption is mistaken. ...It just might be better to have more kids in a class with a better teacher than to divide the students into smaller classes with inferior teachers.

Of course, the real reason for those proposals isn't to encourage hiring new teachers but to increase the rents received by the current stock of teachers.

UPDATE: I also hate former Royals in my bullpen. 8-3 Yankees, middle 7.