Environmental problems and economic development in an endogenous fertility model

Population growth is often viewed as a most oppressive global problem with respect to environmental deterioration, but the relationships between population development, economic dynamics and environmental pollution are complex due to various feedback mechanisms. We analyze society’s economic decisions on birth rates, investment into human and physical capital, and polluting emissions within an optimal control model of the coupled demographic-economic-environmental system. We show that a long-run steady state is optimal that is characterized by a stable pollution stock, and by population and economic growth rates depending on the possibilities of emission abatement and technical progress due to human capital accumulation. We derive a condition on the production technologies and opportunity costs of raising children, under which the optimal birth rate is constant even during the transition to a steady state. In particular in an economy where only human capital is needed to produce output, the optimal choice of the birth rate is not affected by the states of the economy or the environment. In such a setting, the optimal birth rate is constant and policy should concentrate on intertemporal adjustment of per-capita emissions.sustainability, endogenous fertility, externalities

Population growth and environmental deterioration: An intertemporal perspective

Population growth is often viewed as a most oppressive global problem with respect to environmental deterioration. In this paper, we investigate the optimal development of a coupled system comprising population, economy, and the natural environment as subsystems. In our formal dynamic model these are interrelated by the society’s economic decisions on consumption, birthrate, and emissions. Considering Hicks neutral technical progress, we find a steady state with growing population and declining per capita emissions, all other variables remaining constant over time. We investigate the comparative static properties of the steady state, and the dynamic behavior of the system. In numerical simulations we show that simple variations in the dynamics of the subsystems lead to complex and sometimes qualitatively different behavior of the coupled system. This is a challenge for policy advice based on such inter-temporal optimization models

Environmental problems and economic development in an endogenous fertility model

Population growth is often viewed as a most oppressive global problem with respect to environmental deterioration, but the relationships between population development, economic dynamics and environmental pollution are complex due to various feedback mechanisms. We analyze society’s economic decisions on birth rates, investment into human and physical capital, and polluting emissions within an optimal control model of the coupled demographic-economic-environmental system. We show that a long-run steady state is optimal that is characterized by a stable pollution stock, and by population and economic growth rates depending on the possibilities of emission abatement and technical progress due to human capital accumulation. We derive a condition on the production technologies and opportunity costs of raising children, under which the optimal birth rate is constant even during the transition to a steady state. In particular in an economy where only human capital is needed to produce output, the optimal choice of the birth rate is not affected by the states of the economy or the environment. In such a setting, the optimal birth rate is constant and policy should concentrate on intertemporal adjustment of per-capita emissions

Effective risk governance for environmental policy making: a knowledge management perspective

Effective risk management within environmental policy making requires knowledge on natural, economic and social systems to be integrated; knowledge characterised by complexity, uncertainty and ambiguity. We describe a case study in a (UK) central government department exploring how risk governance supports and hinders this challenging integration of knowledge. Forty-five semi-structured interviews were completed over a two year period. We found that lateral knowledge transfer between teams working on different policy areas was widely viewed as a key source of knowledge. However, the process of lateral knowledge transfer was predominantly informal and unsupported by risk governance structures. We argue this made decision quality vulnerable to a loss of knowledge through staff turnover, and time and resource pressures. Our conclusion is that the predominant form of risk governance framework, with its focus on centralised decision-making and vertical knowledge transfer is insufficient to support risk-based, environmental policy making. We discuss how risk governance can better support environmental policy makers through systematic knowledge management practices

Der Diskurs über Nachhaltigkeit und die Rolle der ökologischen Ökonomie

Der Autor erörtert den Zusammenhang zwischen Gesellschaft und Umwelt aus wissenschafts- und wirtschaftssoziologischer Perspektive und geht insbesondere auf die Ansätze der ökologischen Ökonomie ein. Diese hat sich in Abgrenzung zu der von ihr als neoklassisch bezeichneten Umweltökonomie in den 1090er Jahren international etabliert. Sie hat in theoretischer Hinsicht die relevanten Konfliktlinien in der Selbstbeschreibung des ökonomischen Systems aufgezeigt. Die wissenschaftssoziologische Fragestellung eröffnet gegenüber einer rein wirtschaftssoziologischen Betrachtung die Möglichkeit, die theoretische Selbstbeschreibung der Wirtschaft in zwei Richtungen empirisch zu befragen: Sie kann zum einen untersuchen, wie ökologisches Wissen vom Markt adaptiert wird. Zum anderen kann sie aber auch Widersprüche der theoretischen Selbstbeschreibung beobachten und diese unter Berücksichtigung sozialer Fakten soziologisch verstehen. Dieses soziologische Verstehen, d.h. die makrotheoretische Kontextualisierung, entzieht sich aber regelmäßig der Selbstreflektion der Ökonomik. Dennoch kann von einer relativen Autonomie der Ökonomik gegenüber ihrem Gegenstandsbereich ausgegangen werden, was sich - wie der Autor in seinem Beitrag näher zeigt - als systemische Reflexion auf die ökologische Krise verstehen lässt. (ICI2

Is a Sustainable Land-Use Policy in Germany Possible?

Land is an essential but limited natural resource. We employ the concept of stocks to analyse driving forces for land-use conversion and to assess, whether the German political "30- hectares-goal" is feasible given the current institutional setting. In this paper major driving forces for land-use conversion are identified and underlying stocks and persistent institutional structures as well as their dynamics are investigated. It will be shown that meeting the 30- hectares-goal is unlikely. We further argue that due to persistent stocks and institutional structures land-use conversion from agricultural into urbanised land takes place on smaller time scales than its reconversion. We conclude that demographic change and regional migration processes may result in further land-use conversion even with declining population. Economic structural change as well as an increasing traffic volume will likewise contribute to further land-use conversion

Application of a Broadband Active Vibration Control System to a Helicopter Trim Panel

This paper discusses testing of a broadband active vibration control concept on an interior trim panel in a helicopter cabin mockup located at ONERA's Centre de Toulouse. The control system consisted of twelve diamond-shaped piezoelectric actuators distributed around a 1.2m x 1.2m trim panel. Accelerometers were mounted at the four vertices of each diamond. The aspect ratio of the diamond was based on the dielectric constants of the piezoelectric material in order to create an actuator-sensor pair that was collocated over a broad frequency range. This allowed robust control to be implemented using simple, low power analog electronics. Initial testing on a thick acrylic window demonstrated the capability of the controller, but actuator performance was less satisfactory when mounted on a composite sandwich trim panel. This may have been due to the orthotropic nature of the trim panel, or due to its much higher stiffness relative to the acrylic window. Insights gained from a finite element study of the actuator-sensor-structural system are discussed