The time value of money.

A couple of things to keep in mind as you read about the Yankees' free agent signings:

1) The Yankees didn't just write a check for $180 million and give it to Mark Teixeira. This money will be paid over 8 years. By the time the contract expires, Teixeira will be a bargain and the 50th highest-paid player in baseball. David Wright will be paid $35M in the year 2017.

Eight years ago, Albert Belle* was the highest-paid player in baseball and he got paid what Julio Lugo got paid in 2008.

* When I first wrote that, I thought I was exaggerating, but then I looked it up on baseball-reference.com and that is actually quite close to the truth. Belle was paid $12.9M in 2000 and Lugo was paid $9.25M in 2008.

2) $420 million is not really "almost" $500 million.

It's 84% of $500 million.

If 84%= 100%, then the Dow Jones Industrial Average is still at 10,000, this country is not in a recession, and Bernie Madoff's clients are not killing themselves.

If 84% = 100%, then the Yankees won 106 games last season.