The expansion of private production erodes the quality of commonly owned assets, thereby forcing individuals to rely increasingly on private goods to satisfy their needs. In the face of this deterioration, households increase their work effort and accumulate more capital in order to buy more consumer goods both in the present and in the future. By so doing, each household contributes to an increase in production and thus has a detrimental—though negligible—impact on commonly owned assets. Hence, the economy converges to a long-run equilibrium level of production that is higher than the level associated with the Pareto-efficient path.

A decade has now passed since Daly made a plea for an environmental macroeconomics. Despite an expanding literature on ‘green’ national accounting and the efforts of ecological economists to measure the sustainable net benefits of a growing macroeconomy, it is only recently that Daly's plea has been adequately answered. This has been achieved with the incorporation by Heyes of an ‘environmental equilibrium’ or EE curve into the familiar IS–LM model. However, the IS–LM–EE model proposed by Heyes is incomplete. By extending Heyes' model to include the role of technological progress and the sustainable net benefits of economic activity, this paper shows that conclusions regarding the desirability of expansionary fiscal and monetary policies alter quite radically. Moreover, it sends out a clear message that environmental concerns should be incorporated into macroeconomic models. They should not be solely confined to microeconomics.

This paper draws on a number of recent studies to shed light on several policy issues raised by the impact of environmental policies on technological innovation. First, to what extent does induced innovation raise the overall net benefits to society from environmental policies? Second, how does induced innovation affect the appropriate choice among alternative environmental policy instruments? Third, how does it affect the optimal stringency of environmental regulations? Fourth, should environmental policies be supplemented with additional policies to promote innovation, such as research contracts or prizes for new technologies?

This study explores the effects of land tenure institutions on land use and management using household date from cocoa growing areas of Ghana. Various land tenure institutions with different land rights coexist in our sites, such as allocated family land, inherited land, appropriated village land, and land received as gift. While tree planting and the decision to leave land fallow may be affected by land tenure status, there are no significant differences in labor allocation and revenue of both cocoa and food crops among parcels under different land tenure institutions. These results support the hypothesis that management incentives of cocoa fields, but not food crop fields, tend to be equalized due to the incentive-enhancing effects of granting secure land rights after efforts to plant cocoa trees are expended.

Excess capacity and overfishing are problems in the open-access, common-pool fisheries of the Java Sea. Data development analysis is used to estimate excess fishing capacity and the number of vessels to decommission in three Java Sea fisheries of Indonesia, the purse seine, mini purse seine, and longline. First- and second-best policy measures are discussed to reduce the excess capacity and give sustainable management and development. The importance of incentive design, asymmetric information, and the regulator's principal–agent problem are emphasized in license limitation programs.

This paper examines the nature of community management of woodlots and investigates the determinants of collective action and its effectiveness in managing woodlots, based on a survey of 100 villages in Tigray, northern Ethiopia. Despite limited current benefits received by community members, the woodlots contribute substantially to community wealth, increasing members' willingness to provide collective effort to manage the woodlots. We find that benefits are greater and problems less on woodlots managed at the village level than those managed at a higher municipality level, and that the average intensity of management is greater on village-managed woodlots. The factors that do significantly affect collective action include population density (higher collective labor input and lower planting density at intermediate than at low or high density), market access (less labor input, planting density and tree survival where market access is better), and presence of external organizations promoting the woodlot (reduces local effort to protect the woodlot and tree survival). The finding of an inverse U-shaped relationship between population density and collective labor input is consistent with induced innovation theory, with the increased labor/land ratio promoting collective effort to invest in resources as population density grows to a moderate level, while incentive problems may undermine collective action at high levels of population density. These findings suggest collective action may be more beneficial and more effective when managed at a more local level, when the role of external organizations is more demand-driven, and when promoted in intermediate population density communities more remote from markets. In higher population density settings and areas closer to markets, private-oriented approaches are likely to be more effective.

Advances in biotechnology have made available gene-manipulation techniques that enable the protection of genetic material from unauthorized use and the prevention of self-supply of commercial seeds by farmers—in order to allow enhanced appropriation of the values of innovation in agricultural R&D. These techniques have become known as Genetic Use Restriction Technologies (GURTs).

This paper forecasts the potential impact of wide-spread adoption of GURTs by the providers of HYV seeds on the yield development in developing countries. To do so, it assesses (1) the effects of enhanced appropriation through GURTs on the technological expansion at the yield frontier and (2) the effects of technological protection of value-adding traits through GURTS on the diffusion of yield gains from the frontier to developing countries. These assessments are based on a particular hypothesis, which is that GURTs will replicate across most staple crops the experiences that were made with a previous use restriction technology (hybridization) in only a few crops. The estimation of impacts is carried out as a simulation and is based on expansion and diffusion parameters estimated for hybrid seeds over a 38-year period. It shows that the impact of GURTs on developing countries' yields will vary considerably. Specifically, those countries that currently have the lowest yields would be most adversely affected in their future yield development by the wide-spread use of GURTs.

Although genetically modified organisms (GMOs) have recently attracted a great deal of public attention, analysis of their economic impact has been far less common. This paper puts forward variants of a simple model of crop production, each one tailored to a particular aspect of transgenic food technology. The focus is on the possibility of monopolization and its consequential welfare costs. Risk factors identified include moderate cost savings from transgenic varieties, high seed storage costs, and high risks of crop loss. The paper also discusses some of the possible remedies including tighter regulation of anti-competitive practices and liberalization of the regulations governing the introduction of new GMOs.

The terminator gene can render seeds sterile, so forcing farmers to purchase fresh seed every year. It is a technological solution to the problem of market failure that could increase the appropriability of R&D investment more effectively than intellectual property rights legislation or patents. This paper shows that appropriability should be more than tripled and that this leads to greater private R&D investment, which may be expected to double or triple. This would bring open-pollinating varieties into line with F1 hybrids, for which seed cannot be saved. In turn, the increased investment should raise yield increases to levels similar to those for hybrid crops. Thus, there are benefits to set against the possible ecological and environmental costs and the clear distributional and social consequences. The paper discusses the way the seed market is developing, the possible impacts, especially from a developing country viewpoint, and considers the policy changes that are needed.