This paper shows that compromise between different ideologicalmotivations within multiparty governments may result in a biastoward running budget deficits even if all parties in thecoalition prefer balanced budgets. The deficit bias increases withthe degree of ``polarization'' of the ideological motivations andgenerally decreases with the degree of concentration of powerwithin the government. Although the analysis is conducted assuminga proportional representation electoral system, the results willalso apply to majoritarian systems if the winning party comprisesideologically different constituencies. The relationship betweenbudget deficits and multiparty governments is investigated usingdata from a sample of eight European Union countries for the period1971–1990. Analysis on pooled data is partly in line with the theory.Time series within country analysis is less favorable: we findclear support to the theory only in the case of Italy.