Stephen Dubner

The answer to that question has to do with something that happened in 2011.

That's coming up after the break.

I'm Stephen Dubner, and you were listening to Freakonomics Radio.

Last year, the economist Roland Fryer and I teamed up to try to learn why running back salaries have fallen so much since their heyday.

Salaries are driven in part by where a player is selected in the NFL draft.

In 1990, 12 running backs were taken in the first two rounds of the draft.

Last year, there were two.

So what's driving this decline?

We've already heard about the analytics revolution that showed the value of passing versus running.

We've heard about rule changes the NFL adopted to privilege the passing game.

But there was another big change in 2011 that shook things up for NFL rookies generally and running backs in particular.

team has control of you for five years.

That is Robert Turbin.

He was an NFL running back for four teams over eight seasons, including a Super Bowl win with the Seattle Seahawks.

Today, he does football commentary for CBS Sports.

Roland Fryer spoke with him.

The CBA is the collective bargaining agreement, the contract between NFL teams and the NFL Players Association, the union that represents the athletes.

The negotiations over a CBA are long and often contentious as they establish pay standards and other terms for years to come.

The current CBA was agreed to in 2020 and runs through the 2030 season.

The one before that went into effect in 2011.