Lower-house seat shares best measure postcommunist party political influence.

Evidence

Focusing on only lower house elections for this time period is justified for two reasons. First, not all of the emerging constitutional orders of Eastern Europe and the former Soviet Union are identical: some are unicameral, as is the case in Albania, Bulgaria, Hungary, and the Baltic States; others, such as the Czech and Slovak Republics, Russia, Poland, and Romania have bicameral legislatures. Yet in all of the latter the more powerful house is the lower house. Therefore, for the sake of comparability, I concentrate only on the lower houses of the legislatures. Second, I focus on legislatures instead of presidencies because, although in many of these postcommunist political systems, a relatively powerful and directly elected executive exists (such as in Russia, Poland, Romania, Bulgaria, Belarus, and Ukraine), the executive throughout postcommunist Eastern Europe has sought some accommodation with the lower house of parliament. … Focusing on only seat shares as a measure of success rather than the percentage of the vote received by the party is also justified, because control of seats is what counts in terms of government formation and political influence. — John T. Ishiyama, Party Organization and the Political…, 25