Pollution-reducing infrastructure and urban environmental policy

Based on a case study on Bombay, we argue that urban infrastructure, like the sewage system and the municipal waste collection, is an important instrument for urban environmental policy. We develop a spatial general equilibrium model of a monocentric city, where infrastructure serves as a public means of abating pollution. Analyzing the optimal supply of pollution-reducing infrastructure, we conclude that it has to be geographically differentiated, even if pollution is homogenous. In a city with a growing population the provision of infrastructure has to be changed throughout the city, not only in newly inhabited areas. Urban environmental policies, based on Pigouvian taxes and pollution-reducing infrastructure, are mutually dependent. In two settings of public or private infrastructure, we show that fiscal environmental policies have to be spatially differentiated, and that income transfers are necessary in order to implement the first best allocation as a residential market equilibrium. --urban environmental policy,pollution-reducing infrastructure,spatial environmental economics,unequal treatment of equal

The private and public insurance value of conservative biodiversity management

The ecological literature suggests that biodiversity reduces the variance of ecosystem services. Thus, conservative biodiversity management has an insurance value to risk-averse users of ecosystem services. We analyze a conceptual ecological-economic model in which such management measures generate a private benefit and, via ecosystem processes at higher hierarchical levels, a positive externality on other ecosystem users. We find that ecosystem management and environmental policy depend on the extent of uncertainty and risk-aversion as follows: (i) Individual effort to improve ecosystem quality unambiguously increases. The free-rider problem may decrease or increase, depending on the characteristics of the ecosystem and its management; in particular, (ii) the extent of optimal regulation may decrease or increase, depending on the relative size of private and external effects of management effort on biodiversity; and (iii) the welfare loss due to free-riding may decrease or increase, depending on how biodiversity influences ecosystem service provision; it increases, unless higher biodiversity greatly decreases the variance of ecosystem services. --biodiversity,ecosystem services,ecosystem management,free-riding,insurance,public good,risk-aversion,uncertainty

Pollution and the Efficiency of Urban Growth

We analyze the efficiency of urbanization patterns in a dynamic model of endogenous urban growth with two sectors of production. Production exhibits increasing returns to scale on aggregate. Urban environmental pollution, as a force that discourages agglomeration, is caused by domestic production. We show that cities are too large and too few in number in equilibrium, compared to the efficient urbanization path, if economic growth implies increasing aggregate emissions. If, on the other hand, production becomes cleaner over time (`quality growth') the urbanization path approximates the efficient outcome after finite time.Cities, Urbanisation, Pollution, Growth, Migration, Sustainable Development

Managing increasing environmental risks through agro-biodiversity and agri-environmental policies

Agro-biodiversity can provide natural insurance to risk-averse farmers by reducing the variance of crop yield, and to society at large by reducing the uncertainty in the provision of public-good ecosystem services such as e.g. CO2 storage. We analyze the choice of agro-biodiversity by risk-averse farmers who have access to financial insurance, and study the implications for agri-environmental policy design when on-farm agro-biodiversity generates a positive risk externality. While increasing environmental risk leads private farmers to increase their level of on-farm agro-biodiversity, the level of agro-biodiversity in the laissez-faire equilibrium remains ineciently low. We show how either one of two agri-environmental policy instruments can cure this risk-related market failure: an ex-ante Pigouvian subsidy on on-farm agro-biodiversity and an ex-post compensation payment for the actual provision of public environmental benefits. In the absence of regulation, welfare may increase rather than decrease with increasing environmental risk, if the agroecosystems is characterized by a high natural insurance function, low costs and large external benefits of agro-biodiversity.agro-biodiversity, ecosystem services, agri-environmental policy, insurance, risk-aversion, uncertainty

Natural vs. financial insurance in the management of public-good ecosystems

In the face of uncertainty, ecosystems can provide natural insurance to risk averse users of ecosystem services. We employ a conceptual ecological-economic model to analyze the allocation of (endogenous) risk and ecosystem quality by risk averse ecosystem managers who have access to financial insurances, and study the implications for individually and socially optimal ecosystem management, and policy design. We show that while an improved access to financial insurance leads to lower ecosystem quality, the effect on the free-rider problem and on welfare is determined by ecosystem properties. We derive conditions on ecosystem functioning under which, if financial insurance becomes more accessible, (i) the extent of optimal regulation increases or decreases; and (ii) welfare, in the absence of environmental regulation, increases or decreases.ecosystem quality, ecosystem services, ecosystem management, endogenous environmental risk, insurance, risk-aversion, uncertainty

The Private and Public Insurance Value of Conservative Biodiversity Management

The ecological literature suggests that biodiversity reduces the variance of ecosystem services. Thus, conservative biodiversity management has an insurance value to risk-averse users of ecosystem services. We analyze a conceptual ecological-economic model in which such management measures generate a private benefit and, via ecosystem processes at higher hierarchical levels, a positive externality on other ecosystem processes at higher hierarchical levels, a positive externality on other ecosystem users. We find that ecosystem management and environmental policy depend on the extent of uncertainty and risk-aversion as follows: (i) Individual effort to improve ecosystem quality unambiguously increases. The free-rider problem may decrease or increase, depending on the characteristics of the ecosytsem and its management; in particular, (ii) the size of the externality may decrease or increase, depending on how individual and aggregate management effort influence biodiversity; and (iii) the welfare loss due to free-riding may decrease or increase, depending on how biodiversity influences ecosystem service provision.biodiversity, ecosystem services, ecosystem management, free-riding, insurance, public good, risk-aversion, uncertainty

What is sustainability economics?

While economists have been contributing to the discussion of various aspects of sustainability for decades, it is just recently that the term “sustainability economics” was used explicitly in the ecological, environmental, and resource economics community. Yet, the contributions that use the term “sustainability economics” do not refer to any explicit definition of the term, and are not obviously joined by common or unifying characteristics, such as subject focus, methodology, or institutional background. The question thus arises: What is “sustainability economics”? In this essay, we make an attempt at systematically defining and delineating what “sustainability economics” could be in terms of its normative foundation, aims, subject matter, ontology, epistemology, and genuine research agenda.economics, efficiency, epistemology, fairness, future, justice, human-nature-relationship, ontology, philosophy of science, sustainability, uncertainty

Agro-biodiversity as natural insurance and the development of financial insurance markets

Agro-biodiversity can provide natural insurance to risk averse farmers. We employ a conceptual ecological-economic model to analyze the choice of agrobiodiversity by risk averse farmers who have access to financial insurance. We study the implications for individually and socially optimal agro-ecosystem managementand policy design when on-farm agro-biodiversity, through ecosystem processes at higher hierarchical levels, generates a positive externality on other farmers. We show that for the individual farmer natural insurance from agro-biodiversty and financial insurance are substitutes. While an improved access to financial insurance leads to lower agro-biodiversity, the eects on the market failure problem (due to the external benefits of on-farm agro-biodiversity) and on welfare are determined by properties of the agro-ecosystem and agro-biodiversity’s external benefits. We derive a specific condition on agro-ecosystem functioning under which, if financial insurance becomes more accessible, welfare in the absence of regulation increases or decreases.agro-biodiversity, ecosystem services, agro-ecosystem management, insurance, risk-aversion, uncertainty

Optimal grazing management rules in semi-arid rangelands with uncertain rainfall

We study optimal adaptive grazing management under uncertain rainfall in a discrete-time model. As in each year actual rainfall can be observed during the short rainy season, and grazing management can be adapted accordingly for the growing season, the closed-loop solution of the stochastic optimal control problem does not only depend on the state variable, but also on the realization of the random rainfall. This distinguishes optimal grazing management from the optimal use of most other natural resources under uncertainty, where the closed-loop solution of the stochastic optimal control problem depends only on the state variables. Solving this unusual stochastic optimization problem allows us to critically contribute to a long-standing controversy over how to optimally manage semi-arid rangelands by simple rules of thumb.environmental risk, risk management, stochastic optimal control, grazing management, rules of thumb

Ecological-economic viability as a criterion of strong sustainability under uncertainty

Strong sustainability, according to the common definition, requires that different natural and economic capital stocks have to be maintained as physical quantities separately. Yet, in a world of uncertainty this cannot be guaranteed. To therefore define strong sustainability under uncertainty in an operational manner, we propose to use the concept of viability. Viability means that the dierent components and functions of a dynamic, stochastic system at any time remain in a domain where the future existence of these components and functions is guaranteed with suciently high probability. We develop a unifying and general ecological-economic concept of viability that encompasses the traditional ecological and economic notions of viability as special cases. It provides an operational criterion of strong sustainability under conditions of uncertainty. We illustrate this concept and demonstrate its usefulness by applying it to livestock grazing management in semi-arid rangelands.capital (natural and economic), ecological-economic systems, ecosystem services, funds, stocks, sustainability, uncertainty, viability