On the Peaking of Consumption with Exhaustible Resources and Zero Net Investment

We investigate an intertemporal model with an exhaustible resource inflowwhich exhibits a single peak in consumption on the path of development. Thepeak follows the date at which net investment is zero. The ``top' ofconsumption is higher and flatter and peaks later when the discount rate islower. ``Low' endowments of the exhaustible resource stock (and ``high'discount rates) are associated with strictly declining consumption paths.     

Encephalization and division of labor by early humans

We draw on Ricardian comparative advantage between distinct persons to map out the division of labor among proto-humans in a village some 1.7 million years ago. A person specialized in maintaining a cooking fire in the village is of particular interest (Ofek, Second nature, economic origins of human evolution, Cambridge University Press, New York, 2001). We are also interested in modeling hunting by village males in teams. The large issue is whether and how specialization (division of labor) and interpersonal trade might have driven brain-expansion in early humans. We emphasize the need for early humans to develop the capacity to see themselves in others’ shoes (other-regardingness) in order for regularized trading to follow division of labor.     

Competition in NHS quasi-markets

Recent reforms of the National Health Service have focused attentionon both contracts for health services and competition amongstthe providers of those services as means of ensuring that qualityis maintained at an acceptable standard whilst costs are contained.This paper considers the particular roles that competition maybe expected to play in both health authority and GP fundholderquasi-markets.     

对朱兰博士的缅怀和追忆

一代质量伟人朱兰博士2008年2月29日去了。在悲伤和悼念之余，有着更多的缅怀。 记得第一次见到朱兰博士是在1982年，那年，在国家经委的支持下，中国质协邀请朱兰博士来华讲学，我因奉命组织培训班，得以聆听他的讲课，并能与自己仰慕的专家多一点近距离接触。     

Efficient land use in an equilibrium residential annulus

An efficient land use is one in which land is divided between residential activity and roads so as to minimize aggregate transportation costs. We analyze such an allocation for the case in which each consumer is in equilibrium. The problem synthesizes the approaches in the Mills-de Ferranti analysis and the Solow analysis. In Solow's analysis consumers were in equilibrium but land was allocated by rule of thumb; in that of Mills and de Ferranti land was efficiently allocated in aggregate but each consumer was allocated a fixed area for his residence. Our efficient allocation has a Nash equilibirum characterization. The efficient land allocation is characterized by declining convex functions of distance from the CBD for density on roads and for land rents. The nature of the pattern of land in road use is investigated.     

Increasing returns,exhaustible resources,and optimal growth

It is shown that in an optimal growth model having inputs of flows from an exhaustible resource and services of reproducible capital, constant returns to scale is boundary separating paths of non-steady state development from those of steady development including asymptotic steady state growth. The absence of growth in output was observed by Dagsupta and Heal, and Solow for the case of non-increasing returns to scale.     

The Tragedy of the Commons Revisited

The Malthus–Hardin tragedy of the commons is formulated as a dynamic game between "clans". At each date a member of a clan desires more newborns of her/his type and more current consumption, harvested from the commons. Equilibrium in the dynamic game yields a steady state level of per capita consumption and a steady population level for each clan (births equal deaths). Four outcomes are obtained, depending on the assumptions about the discount rates of members of a clan and about the mode of competition for "large populations" for each clan. Lack of property rights for agricultural land in the commons leads to equilibrium with excessive populations and low per capita consumption.