Abstract: | In this paper I elaborate a recently advanced argument about government formation, and assess it by studying the factions of the Italian Christian Democratic Party (DC). I contend that the costs of making and breaking coalitions depend on political institutions and on the configuration of actors in policy space. Comparisons across parties in Italy and other countries support this argument. So also do comparisons across party factions. The Christian Democratic factions that incurred the lowest office costs to build coalitions were those at or near the left–right median in Italy's core party. When electoral rules were rewritten in the DC, internal party competition over portfolio allocation changed as well. The paper's conclusion outlines how the argument would guide further research on party factions. |