There’s Weitzman (1979), which included both brilliant insights on optimal search theory and a brilliant reference to Greek mythology in form of “Pandora’s Problem.” There’s Weitzman (1976) and Weitzman (1998), spanning his work on green accounting and welfare. There’s Weitzman (1992) and Weitzman (1993), introducing set theory and economic thinking into species conservation. There’s Weitzman (2007), a brilliant new take on the equity risk premium puzzle that appears to have eluded financial economists for decades. That insight, in turn, led to Weitzman (2009) and Weitzman (2011) and Weitzman (2012), which introduce fat tails into the climate debate, something that had eluded climate economists. There’s Weitzman (2001), Weitzman (2010), and Weitzman (2012), sparking hundreds of papers and epic debates on how to think about discounting the distant future. There’s Weitzman (1984), followed by Weitzman (1985a) and Weitzman (1985b) and Weitzman (1985c), introducing the Share Economy, on how and why workers should partake in profit sharing, an idea a New York Times editorial called the “best idea since Keynes.” Then there’s Weitzman (1974), Prices vs. Quantities, the brilliant analysis of when to price versus when to limit emissions that launched the field of instrument choice, sparked policy debates the world over, and launched many an environmental economist’s career.
There are dozens more such papers, many offering brilliant insights into important questions, often using complex math to solve seemingly intractable problems, offering conclusions typically summarized in a simple equation or cleverly chosen bon mot.
Then there’s Marty the teacher, person, and mensch. The kid from the Lower East Side who never did lose his New York accent. The person who, as a young professor in Cambridge, MA, bought a small, barren island in a marsh in Gloucester, MA, to build a refuge from academic life, a place where he taught himself Bayesian statistics in his sixties to write that equity risk premium puzzle paper, and where he went on a daily swim well into his seventies.
Weitzman was an academic’s academic, a theoretician’s theorist—someone who eschewed the trends in his discipline toward churning out ever more empirical analyses with larger and larger data sets and more and more coauthors. He appreciated and admired the efforts of those who did dive into thorny empirical questions with increasingly powerful computers. His preferred tools: a No. 2 pencil, a legal pad, and a hard wooden chair.
His study at the home he shared with his wife, Jennifer Bäverstam Weitzman, in Waban, MA, included just that. The laptop served mainly as a repository of papers and as a communications device. While Jennifer gave piano lessons in the living room, he focused on his next idea, playing his recorder whenever he felt his mind wander to refocus at the problem at hand.
It was this relentless focus on getting every model, every equation, every sentence just so that yielded some of the most consequential papers in all of environmental economics, his chosen field, and economics more broadly. Prices vs. Quantities began as a study of the Soviet economy, whether price or quantity controls yielded better results. The resulting paper attests to Weitzman’s intellectual nimbleness. His first submission was met with a rejection, and a reviewer’s comment that he might want to tackle a different set of questions, emerging in the early 1970s: whether to price or limit pollution. He recast the paper, his most cited work to date, and refocused a good part of his subsequent work on environmental problems and their solution.