tag:blogger.com,1999:blog-2807806767960745481.post8832956029948883799..comments2024-03-18T00:44:03.742-07:00Comments on The Least Thing: Quantifying the Value of a Football ManagerRoger Pielke, Jr.http://www.blogger.com/profile/04711007512915460627noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-2807806767960745481.post-85118234458869804832012-01-28T11:24:41.983-08:002012-01-28T11:24:41.983-08:00Stefan-
Many thanks for the comment ... a few tho...Stefan-<br /><br />Many thanks for the comment ... a few thoughts in reply:<br /><br />1. If you look at the figure above from UEFA on the relationship of wages and success, you can see evidence that the wage effect diminishes as wages increase, which would tend to support the idea of bi-directionality in wages <--> success (or at least an intervening variable, like a Sheik!).<br /><br />2. With so much variance explained by wages (in the data that you cite, reproduced at the top of this post from your book), the "manager effect" is likely to be small in many cases and difficult to detect in the best of situations (small N problem).<br /><br />3. I agree that a "manager effect" that persists over time and (especially) across teams is the most likely to be identified.<br /><br />4. Given the non-stationary nature of the data and underlying relationships, I am not sure that aggregate statistical methods are possible of resolving the "manager effect." Perhaps a focus on manager decision making (e.g., evaluating the consequences of decisions on line-ups, substitutions, transfers, etc.) might also bear some fruit. Data which shows that manager that (a) performs above average according to aggregate statistics, and (b) can be shown to make good decisions based on their outcomes (over time), would be convincing to me, in fact, I'd expect (b) to largely cause (a).<br /><br />Thanks again!!Roger Pielke, Jr.https://www.blogger.com/profile/04711007512915460627noreply@blogger.comtag:blogger.com,1999:blog-2807806767960745481.post-53176967998675775512012-01-28T11:06:50.283-08:002012-01-28T11:06:50.283-08:00Comment by email for posting from Stefan Syzmanski...Comment by email for posting from Stefan Syzmanski ...<br /><br />"I'm not sure I exactly agree with the way you explain the problem, but I agree there is a problem. I would start with wages.<br /><br />How do we know that wages cause success rather than successful teams choose to pay high wages (reverse causation)? We can argue from theory - why would owners choose to pay high wages if they didn't need to- why not use the money for something else? I think this is pretty persuasive, but it's not a statistical argument.<br /><br />The statistical problem is that there is no way of separating high wage paying teams from successful teams. Imagine we could randomly assign players to teams, then we would observe the impact of high wages on team performance.<br />Obviously we can't do this, but there is a potential fix. If we can find a variable that is correlated with wages but not causally linked with performance then we can use that in the regression instead of wages.<br /><br />It's tricky to think of such a variable. One example might be climate- teams based in locations with worse climates will usually have to pay more for the same player, so this will be correlated with wages, but presumably is not very closely correlated with performance.<br /><br />However, for my English football club database it would be hard to collect the data over 37 years (does it even exist? And there probably isn't enough variation in climate between teams to make this viable (how would you compare Everton and Liverpool- 1 mile apart?).<br /><br />I'm currently working on the problem with Thomas Peeters, a PhD student from Antwerp who's spending some time over here. Because the football club accounts have so much other information (e.g. balance sheet and profit and loss data), we're hoping that one of these variables might fit closely with wages while having no obvious link to performance.<br /><br />So, if we can solve that statistical problem, I don't think there's too big a problem to attrbuting residual success to the manager. In general a manager is with a club for only a few years, so I think it's hard to believe that there are other factors that will influence performance of the team but only during the tenure of the manager. There are so many managers, and so many of them statistically insignificant, that I think there genuinely is something special about the individual on those rare occasions when something out of the ordinary happens."Roger Pielke, Jr.https://www.blogger.com/profile/04711007512915460627noreply@blogger.com