10
The method of analysis is logit. Because we believe that cases associated with the same
alliance influence one another, we control for non-independence of observations associated with
the same alliance. We used the EUGene computer program to compile many of the independent
variables used in this analysis (Bennett and Stam, 2000). Frequencies of this and all other
independent variables are available in the appendix.
11
While Leeds (2003a) coded as democratic any state with a Polity III democracy score of
five or greater, following the argument by Maoz (1996) that we should recognize a moving
threshold for democracy over time, we employ a threshold of six or greater to be more consistent
18
time period.
Leeds (2003a) argues that the strongest predictors of violated alliance commitments are
changes in domestic regime type and/or international power between the time that the alliance is
formed and when it is invoked. If state leaders have a tendency to form alliances that they are
willing to fulfill, changes in factors that affect decisions for war participation may result in
violations of commitments that might have been fulfilled at the initial conditions. She finds
considerable support for these hypotheses in the 1816-1944 time period; changes in the power of
states and changes in the domestic political institutions of states between the time the alliance is
formed and invoked have a large positive impact on the probability of violation. In addition,
democratic states are less likely to violate alliances, major powers are more likely to violate
alliances particularly to minor powers, and original targets are comparatively likely to find their
allies are unreliable.
Table 1 reports a similar analysis covering the entire period from 1816 through 1991.
10
In
a model including these other variables, the variable representing democracy is positive, but
statistically insignificant. In this larger sample, it appears that democracies are neither more nor
less likely to violate alliances that have been invoked by war than non-democracies once we
control for other factors.
11
Convention