Last weekend France beat Ireland 30-24 in Paris in the second round of this year’s Six Nations rugby championship. The following night the Los Angeles Rams won the Superbowl with a 23-20 win over the Cincinnati Bengals. The connection? A paper published in the Journal of Political Economy back in 2006.
72 minutes into the France-Ireland match, Ireland were awarded a penalty in the French half with France leading 27-21. The Ireland captain, James Ryan, had a big decision to make. He chose to take a shot at goal, and Ireland’s number 10, Joey Carbery, duly slotted a relatively straightforward chance over the bar for three points. The alternative option would have been to kick the ball out of play close to the French goal line and look to score a try off the subsequent line-out, with Ireland having the advantage of throwing the ball into the line-out. A try would have brought Ireland to 26 points, with the possibility of another two points which would have given them a one point lead, with only a few minutes remaining, if they managed to score the subsequent conversion kick. Kicking the penalty, reduced the deficit but still meant that Ireland would have to get back up the pitch to score again if they were to win, following the re-start. More importantly, Ireland would still needed to score a try to win the game. Another penalty would only tie the match.
It is also worth considering the impact of the Irish captain’s choice on league points, since after all, they decide the championship. At 27-21 down, Ireland would have got a losing league bonus point, provided France did not score again. (The French did score a penalty as it happens to win 30-24, but Ireland still got the losing bonus point). Kicking the penalty, however, meant that France would have to score a try to deny Ireland that losing bonus point. However, Ireland had scored three tries at that stage, and a fourth try would have given them a try bonus point. Even if the conversion was unsuccessful, leaving Ireland still a point behind, barring France scoring a converted try, Ireland would have got two bonus points if they lost. A converted French try would have meant just one bonus point for Ireland, for scoring four tries, but that is what they kicked that penalty. Of course, if Ireland had scored the try and converted and held on to win, they would have come away with five points.
Here we turn to that 2006 Journal of Political Economy paper by David Romer, entitled “Do Firms Maximise? Evidence from Professional Football. Romer’s paper sought to test a basic proposition in economics, that economic agents seek to maximise – consumers attempt to maximise utility and firms seek to maximise profits. As Romer points out, the argument for this assumption is not that it represents a perfect description of behavior, but that it leads to reasonably good approximations in most cases. Romer’s paper tests the hypotheses by analysing decisions of American football teams on fourth down. In American Football teams get four plays (downs) to make 10 yards. If they are successful they keep possession for another four downs, the ultimate aim being to get the ball over the opposition goal line for a touchdown, not unlike a try in rugby, as it happens. If they fail to make ten yards after four downs, possession is turned over to the other team. So on the fourth down, teams face a choice between trying to make the ten yards, or kicking the ball downfield, giving up possession as far from their own goal line as possible. Teams could try and score a field goal if they are within kicking range. A field goal, like a penalty in rugby, is worth three points, while a converted touchdown is worth seven. Romer reasoned that, if teams were maximisers, they should go for the ten yards if they were just short on fourth down, rather than kick the ball away. He found, however, that teams’ tended to choose the more conservative kicking option, even though such decisions failed to maximise their chances of winning.
Many rugby pundits argued that Ryan’s decision to take a straightforward three points was the correct one. What would Romer have made of Ireland’s call on 72 minutes in Paris?