One of the greatest proponents of limited government and free markets in the 20th century, Buchanan reminded us that liberty under a just rule of law is essential to a healthy society. Like Adam Smith, Buchanan was interested in the institutions that would allow individuals to pursue their own selfinterest while benefiting others through a system of what Milton Friedman has called “free private markets.”

Buchanan considered the principle of spontaneous order — that is, the harmony and wealth creation that emerges through voluntary exchange when government is limited and rights to life, liberty, and property safeguarded — to be “the most important central principle in economics.”

The primary question that occupied Buchanan during his long career is the problem of constitutional choice — the alternative rules that would best allow individuals the freedom they need to increase their range of choices and bring about social harmony. The proper balance between the state and the individual — or between coercion and consent — is at the foundation of constitutional political economy.

Although Buchanan made substantial contributions to the field of public choice, he was primarily interested in the choice of regimes and how alternative rules would influence behavior. He also strongly criticized both citizen and policy myopia. “Until and unless we begin to take the long‐​term perspective in our private and in our public capacities, including the adoption of new and binding constitutional constraints on the fiscal and monetary powers of government, we are doomed to remain mired in the muck of modern politics,” he once wrote.

Buchanan’s passing leaves a giant void at a time when Western democracies are expanding the size and scope of government and threatening the future of liberty. His vast body of work, however, will continue to live on.