The fact that the majority of players in the treatment group never played for the
national team before suggests that many players in the treatment group know they have
no realistic chance of playing in the Euro 2008. This seems a likely explanation for the
absence of any significant average effect of the Euro treatment.
5.2 Differential Effects: Nomination Chance and Age
Table 7 reports results of regressions concerned with differential effects as a function of
a player’s nomination chance, as proxied by his national team participations since the
last World Cup. The estimates for shots on goal per minute reported in the first column
of Table 7 supports the prediction of the nomination contest theory that players with
uncertain nomination chances should react most strongly. The coefficient of qualified *
natteam(1 - natteam) is positive and significant at the 5% level, while the direct effects
of qualif ied and all other regressors that involve natteam are insignificant. Interpreting
natteam as a player’s current nomination probability, the prediction is a symmetric inverse
U-shaped relationship between a player’s national team nomination probability and the
effect of his nation’s Euro Cup qualification on his club match output. For players with
nomination probabilities around 50% the predicted size of the effect is maximal and
equals about 0.00605; this corresponds to 27% of average pre-treatment shots on goal
per minute for players in the treatment group with natteam-values between 0.4 and 0.6.
The coefficients of the homegame, f orward and midf ield dummies are all positive, as
expected, and highly significant.
For goals per minute, the coefficient of qualif ied * natteam(1 - natteam) is positive
again but insignificant. There is some evidence, however, that uncertainty about being a
regular player on the national team affected Euro Cup 2008 - nationals differently than
other players: while the coefficient of euro * natteam(1 - natteam) is positive, that of
natteam(1 - natteam) is negative. A possible explanation would be that even prior to
the de facto qualifications for the Euro 2008, forward players from likely Cup participants
already started competing for the rare spots on their national teams.
The results for passes received and ball contacts confirm the predictions of both the
nomination contest and the injury theory. For both output measures, the estimated
impact of the Euro Cup treatment is positive for players with intermediate values of
natteam, but negative for players with natteam close to 1. Overall, the results in Table
7 provide a coherent picture in support of the nomination contest and the injury theory:
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