Back in July, I was invited to give a keynote speech at an international conference we hosted in Cambridge. In it, I took the opportunity to look back at Cambridge economics a hundred years ago; 1920s Cambridge economics means Keynes, of course. The 1923 book “A Tract on Monetary Reform” contains the memorable “in the long run, we are all dead.” Well, not a message that an emeritus professor wants to read, so instead I focused on the extraordinary achievements of the remarkable Frank Ramsey.

Ramsey arrived as a student in Cambridge in 1920, joined Keynes at King’s in 1924, and was appointed a lecturer in 1928. He made seminal contributions in philosophy, mathematics and economics, and provided the first English translation and critique of Wittgenstein – as an undergraduate! Ramsey worked on formal logic (Ramsey sentences). In mathematics he made contributions in combinatorics and number theory (Ramsey Numbers) and, relevant to this piece, major breakthroughs in probability theory and Bayesian statistics; he saw himself as a philosopher and mathematician. But he also made highly significant advances in economics, some not recognized for decades.

Some economists may have encountered his work on optimal tax structures (the Ramsey Rule) or on the balance between savings and consumption in society; both led to Nobel prizes for others. The significance of those papers goes far beyond their immediate focus: to solve the mathematical optimisation required, Ramsey used an aggregate utility function that many have argued was the foundation for the rational, utility-maximizing quantitative economic models that dominated the second half of the twentieth and the first decade of the twenty-first century. The papers wrestle with the question of discounting, the balance between the welfare of current and future generations – a key issue in economic debates on climate change – and influenced Pigou. His ideas on probability had a profound effect on von Neumann, leading directly to Game Theory.