8
This might represent the fact that while proportional representation deputies have
stronger incentives to cave to party demands, they may still have an incentive to shop for
the party best able to get them elected. Thus, they may actively switch parties to find the
one best able to reelect them. In their study of the Italian Chamber of Deputies, Heller
and Mershon (2003) found that proportional representation deputies were more likely to
switch, arguing the opposite view that being more beholden to parties meant that
legislators could only satisfy their policy preferences by switching. This difference,
however, dissipates as the value of the party’s label decreases and single-member district
deputies have even less reason to stay with parties.
In the end, party switching behavior is most likely the result of a mix of motives.
Legislators will take into account electoral, institutional, and policy considerations before
attempting to defect from their existing party and select a new one (Aldrich and Bianco
1992; Strom 1990; Desposato forthcoming, Mann 2000; Heller and Mershon 2005). The
assumption that legislators are only guided by one motive overlooks the complexity of
legislator incentives. While reelection certainly is on legislators’ minds, the reality is that
the reelection calculus is impacted by not only institutional factors like the electoral
system, but also the policies they push. Consequently, party switching even in the
Ukrainian Rada could be caused by a mixture of reasons.
From the existing literature, coupled with the results of previous research on the
Rada, we can develop a series of hypotheses to test empirically. Office-seeking
arguments suggest that legislators change and select parties based on electoral
considerations. If true, we can hypothesize two ways factors that might effect legislator
behavior: past electoral success and ties to the powerful Ukrainian executive branch.
Convention