suggest.
One may worry that the results of the regressions with age interactions (or natteam
interactions) could be driven by an underlying relationship between age and nomination
chance. We therefore also ran regressions including interactions with natteam as in (9)
and age interactions as in (10). The qualitative results concerning both interactions
remained unchanged; see the last column of Table 5 for this when minutes played is the
dependent variable.
Results are also be similar to those in Table 8 if we include only observations with
natteamit > 0, thereby restricting the treatment group to players with a realistic nomi-
nation chance. For passes received per minute as the dependent variable, the coefficient
of qualified * (age — age) would be -0.0082 in that case (p-value = 0.011), and for ball
contacts per minute -0.0114 (p-value < 0.001). For both output measures, the effect
is hence stronger once players with no national team experience are excluded. Ideally,
we would like to investigate the effect of age for different nomination chances in more
detail, but unfortunately our data contains a too limited number of treated players with
a national team history for this.
To summarize our findings on the differential effects of the Euro Cup treatment:
1. Players from qualified countries with intermediate national team nomination chances
perform better in club matches (relative to players of other nationalities with similar
national team experience) after their nations’ qualifications for the Euro 2008 than
before.
2. Players from qualified countries with very high national team nomination chances
perform worse in club matches (relative to players of other nationalities with similar
national team experience) after their nations’ qualifications for the Euro 2008 than
before.
3. Along some dimensions, young players from qualified countries perform better in
club matches (relative to players of similar age from other nations) after their na-
tions’ qualifications for the Euro 2008 than before, but old players from qualified
countries perform worse in club matches (relative to players of similar age from
other nations) after their nations’ qualifications for the Euro 2008 than before.
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