A highly puzzling phenomena in politics is why some parliamentary democracies, such as Britain, manage to produce highly durable governments, whereas others, such as Italy, experience governmental instability. This book reports the results of a quantitative investigation of the issue, using an innovative statistical methodology and a new data set covering sixteen West European countries over the entire postwar period. The results fundamentally challenge current theorizing on government survival and point to an alternative perspective on the relationship among governments, parties, and voters.