The More Parties, the Greater Policy Stability

Abstract

This article discusses, models and quantifies the relationship between the number of parties in government and the degree of policy change or instability. Single-party governments, such as those formed in the United Kingdom for several decades, tend to produce very high levels of policy changes and reversals, whereas multiparty coalition governments, such as the ones in Switzerland or Israel, tend to produce a high degree of stability and little policy change. This relationship is studied for 295 elections and the subsequent governments in twenty-four countries since the Second World War. According to the study, there is a strong negative correlation between the number of parties in government and the degree of policy change. The fewer parties in government the more changes, and vice versa.