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assume, that the decision to defect from a party may be based upon the existence of a
satisfying alternative. Models of selection are an improvement, since they allow the
model to include independent variables that measure the characteristics of alternative
selections that might sway a legislator; however, such models may suffer from selection
effects. While the variables used to explain party defection and selection are often
similar, if not the same, the decision to defect from a party may be based on unobserved
factors not found in a selection model. If true, the results of a selection model are open to
selection bias.
This paper attempts to achieve two goals. First, to determine whether the existing
literature on party switching in other contexts can explain the patterns of behavior we see
in post-Soviet Ukraine. Second, I attempt to reach this goal using a new model for party
switching that controls for the selection effects inherent to previous selection models.
The results clearly indicate that party-switching in the Rada follows predictable patterns
based on the broader literature on party. Rada deputies switched for a mixture of reasons
including office-seeking motives, policy motives, and institutional factors. That said, the
results do suggest that office-seeking motives played a greater role. Most importantly,
these results were obtained using a party selection model which controlled for selection
effects.
The rest of the paper will proceed as follows. First, I will present the extant
literature on party switching and discuss the motivations for party switching. Here I will
develop hypotheses to explain party switching in the Ukrainian Rada. Then, I will
discuss the limitations of current methods of modeling party switching. I will then test
the hypotheses using a data set of all legislators in the Ukrainian Rada between 1998 and
Convention