OK, I said earlier that I don't like mixing football and economics. But this is a minor exception.
Q: What is an example of 'substitution goods'?
A: Steven Gerrard and Frank Lampard.
Q: What is the example of 'complementary goods'?
A: One of either Michael Carric or Owen Hargreaves to either one of Gerrard and Lampard.
Q: What is an example of 'non-increasing return to scale'?
A: Having: 1) a 31-year old David Beckham, and 2) Frank Lampard. OK, Beckham is truly the best crosser and deadball specialist. But he makes it up by slowing down the game. He can't pass an opponent and are often easily beaten. Virtually, most of England's threat came from the left. And Lampard -- his passings are awful, and he baloons the ball too often. And worse, he's a Chelsea player!
Q: What is an example of 'opportunity cost?'
A: By dropping Beckham and installing Aaron Lennon in the right wing, how many potential goals should England sacrifice, vs. the potential of getting more goals from the change in style.
Q: What is an example of 'sunk cost?'
A: Eriksson's decision to bring 2 half-fit, one nonprolific and one inexperienced strikers. (Now as Owen is totally injured, he's left with 3.