National health services tend to be introduced by countries with social democratic governments that also have a concentration of political power.

Why do different countries have different healthcare systems? Federico Toth looks at the three major types of healthcare systems in industrialised countries: voluntary insurance, social health insurance, and national health services (NHS). Using evidence from 15 countries, he argues that those countries with left-leaning governments tend to institute an NHS, while those who are right leaning or authoritarian tend to introduce a model based on social health insurance. He also finds that those countries where political power is concentrated on the government’s executive have a greater likelihood of introducing an NHS.