It is with deep sorrow that we inform you of the passing away of Peter Loeb on November 20, 2024.

Here is the obituary: https://www.legacy.com/us/obituaries/news-gazette/name/peter-loeb-obituary?id=56846652.

Peter was a founding editorial board member of Economic Theory in 1991. He was a pioneer in nonstandard analysis and its applications to economics. His 1973 PAMS paper “A combinatorial analog of Lyapunov’s Theorem for infinitesimally generated atomic vector measures” played an important role in the early applications of nonstandard analysis to general equilibrium theory. In particular, it was used to formalize the concept of “many more agents than commodities” and enabled us to properly model perfect competition in another way. The Loeb measure construction, which was introduced by Peter 50 years ago, has led to important applications in many areas, including mathematical economics. Once a theorem is proved for a Loeb measure space of agents, you automatically know that you also have the asymptotic counterpart of the theorem.

Yeneng Sun and Nicholas Yannelis