题 目：From grab to trade:the transitions in welfare models with missing markets
报告人：Michiel A. Keyzer 荣休教授（荷兰阿姆斯特丹自由大学）
主持人：黄季焜 教授
时 间：2025年10月14日 星期二 10:00-11:30
报告地点：北京大学王克桢楼107会议室
报告人简介：
Michiel A. Keyzer is Professor Emeritus in Mathematical Economics at VU University in Amsterdam, Netherlands; Former Director, Centre for World Food Studies. After graduation in 1972, he joined a Club of Rome project on Food for a Doubling World Population. After its completion in 1976, he moved on the International Institute for Applied Systems Analysis (IIASA), in Austria, where he was part of an international team that developed a world food model that found many applications in IPCC studies, among others. In 1978, he returned to VU University as Deputy Director of the newly created Centre for World Food Studies (SOW-VU), which he headed as Director from 1995 until 2014.
He has acquired long expertise in policy analysis for agricultural and rural development, with specialization on formulation of welfare theory based models and their numerical applications to represent a wide range of geographical and institutional features of the economy under study. He developed dedicated algorithms for solving these usually large models, as well as techniques for statistical analysis of the comprehensive set socio-economic and agroecological data needed for their quantification. He has led several studies in several countries in Eastern Europe, Asia, Africa and the Middle-East, and was a long-time adviser of the European Commission in various rounds of reform of the Common Agricultural Policy.
He has published widely in economics and agriculture-related fields, among others an MIT Press handbook on applied general equilibrium models, and a chapter of the Handbook of Development Economics.
From 2003 until 2016, he was Extraordinary Professor and Advisor at CCAP. Since his retirement in 2014, his research has focused on improving the theoretical embedding of economic models into nature and culture, and since 2022, he has taught graduate courses on individual and collective decision making at VU University.
报告内容：
In what did Stone Age economies of a million years ago differ from the present ones? There are many tales telling us about individuals gathering berries and hunting as a member of a larger band, but far fewer about their competing for food within this band. The question matters to present-day economics because it asks about human choices and relations in settings without formal institutions like markets. Nowadays, most societies combine well-functioning markets for many goods with poorly functioning markets for some, those related to environmental and cultural resources in particular. This makes these resources prone to overexploitation, and to persistent confrontations between rival users. At the same time, furthering commercialization by extending the range of markets is not always possible, or desirable in fact, for example if this would primarily benefit rent-seekers or racketeers. Rather than tracing the historical evolution toward commerce and attempting to explain it, the presentation discusses how to model a succession of transitions from grab, as uncoordinated but non-violent competition for a scarce good in an imaginary Stone Age past, to trade as voluntary exchange of goods. It presents a series of theoretical models that, within a (computable) general equilibrium framework, can account for multi-agent rivalry in multiple goods and keep track of the welfare impact of the transitions.