Government coalitions and legislative success under presidentialism and parliamentarism

Are government coalitions less frequent under presidentialism than under parliamentarism? Do legislative deadlocks occur when presidents do not form majoritarian governments? Are presidential democracies more brittle when they are ruled by minorities? We answer these questions observing almost all democracies that existed between 1946 and 1999. It turns out that government coalitions occur in more than one half of the situations in which the president's party does not have a majority, that minority governments are not less successful legislatively than majority coalitions in both systems, and that the coalition status of the government has no impact on the survival of democracy in either system. Hence, whatever is wrong with presidentialism, is not due to the difficulty of forming coalitions.