McCloskey's example of fungibility in basketball To illustrate the concept of fungibility, Deirdre McCloskey (1985, p. 7, PDF) gives an example from basketball. 

She claims that the last two points scored are no more important than any two points scored earlier:


  The University of Iowa beats the University of Michigan for the Big
  Ten basketball championship by two points in double overtime, 70 to
  68. Whose two points won the game? One's first thought is to look to the last points made. But points are fungible. Any two points can be
  viewed as the crucial points that make the difference between a score
  of 68 to 68 and 70 to 68. The shot that Weisskoff made in the first 5
  minutes of play counts as much as the last. For the purpose of making
  the score what it is, there is effectively no last, no crucial, point.


Is this analysis correct? And if not, in what sense are the last two points more important than any two points scored earlier?



Two examples to illustrate the connection here to economics:

Example 1. Two politicians A and B are running for village mayor. The electoral process in this village is unusual — the two politicians have 12 hours to take turns going door-to-door soliciting votes. The end result is that politician A beats politician B by 35 votes to 34.

Question: Is the first vote scooped up by politician A just as important as the last vote?



Example 2. Two Girl Scouts C and D go door-to-door trying to sell boxes of Girl Scout cookies. The Girl Scout who sells the most wins Girl Scout of the Month. The final score is 35 to 34, with Girl Scout C winning by one box. 

Question: Is the first box sold by Girl Scout C just as important as the last box sold?
In economics and finance, fungibility means that we cannot distinguish between instruments. For example, we normally do not care whether we have one \$20 bill or two \$10 bills.

McCloskey's example is poor. In one sense, it is correct: when points are scored do not matter in the final tally. However, it is psychologically incorrect when applied to sports.

For example, in ice hockey, it is somewhat common to pull your goalie if you are behind at the very end of the game. You have a slightly greater chance of scoring since you have an extra attacker, but it is very easy for the other team to score if they get control of the puck. If you were leading 1-0, and then scored a second goal because the other team pulled their goalie, no sensible hockey fan would weigh the second goal as much as the first. The game was already effectively won by the earlier goal, and the second was just a statistic.

More generally, a team's effort during the game probably reflects the score. Piling up points early may be dangerous, as the team will then relax and sit on its lead. Therefore, later points are effectively more valuable. In order for McCloskey to be correct, we have to believe that the score of the game does not influence behaviour.

These problems do not crop up when using \$10 bills in your example.