دانلود مقاله ISI انگلیسی شماره 12034
عنوان فارسی مقاله

تاثیر حفاظت از انرژی در فن آوری و رشد اقتصادی

کد مقاله سال انتشار مقاله انگلیسی ترجمه فارسی تعداد کلمات
12034 2003 21 صفحه PDF سفارش دهید محاسبه نشده
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عنوان انگلیسی
The impact of energy conservation on technology and economic growth
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : Resource and Energy Economics, Volume 25, Issue 1, February 2003, Pages 59–79

کلمات کلیدی
- رشد اقتصادی - انرژی - نوآوری
پیش نمایش مقاله
پیش نمایش مقاله تاثیر حفاظت از انرژی در فن آوری و رشد اقتصادی

چکیده انگلیسی

We present a model of growth driven by energy use and endogenous factor-augmenting technological change. Both the rate and direction of technological progress are endogenous. The model captures four main stylised facts: total energy use has increased; energy use per hour worked increased slightly; energy efficiency has improved; and the value share of energy in GDP has steadily fallen. We study how energy conservation policies affect growth over time and in the long run. Policies that reduce the level of energy use are distinguished from those that reduce the growth rate of energy inputs. Although these policies may stimulate innovation, they unambiguously depress output levels. The former policy has no impact on long-run growth; the latter reduces long-run growth both in the short run and in the long run.

مقدمه انگلیسی

Central to the economic analysis of climate change policies are the interactions among energy use, technological change and economic growth. The stabilisation of greenhouse gas concentrations requires reductions in fossil fuel energy use, which is a major essential input throughout all modern economies. Cuts in energy use are likely to seriously affect GDP and economic growth. However, if energy conservation can be realised through new energy efficient technologies, the trade-off between energy reduction and growth becomes less severe. Economists have increasingly stressed the crucial role of technical change in the context of climate change, environmental and energy policy (see Loeschel, 2002, for a survey). It is found that the cost of such policies crucially depends on how fast energy efficiency improves. Technical change should be viewed as an endogenous variable: either directly or through changing energy prices, policies may induce innovation by providing incentives to allocate more resources to the development of energy-saving technologies. Climate policy assessments based on the conventional assumption of autonomous energy efficiency improvements ignore these effects. This is why recent studies stress evidence of induced technical change (see Jaffe et al., 2000), focus on learning effects associated with abatement activities and clean technology, and turn to (mostly ad hoc) modelling of induced technical change (see the survey by Azar and Dowlatabadi, 1999). To enhance our understanding of how environmental and energy policies induce technical change, and how they affect economic growth, we need a general-equilibrium analysis of the allocation of research and development activities in the total economy. Policy may not only affect innovation related to energy and clean technologies, but may also crowd out other innovation projects when changing the direction of technical change. We need to know how policy affects the direction of innovation as well as the aggregate rate of innovation. The interaction between these two is neglected in most of the literature so far. The aim of this paper is to develop a growth model in which energy is an essential input and endogenous technical change drives long-run growth. We require that this model is consistent with the main stylised facts concerning energy use and growth. We model innovation as rational investment behaviour driven by profit maximisation. We build the model in order to find analytical results concerning the effects of a reduction in energy use (“energy conservation”) on the rate and direction of technical change, and on GDP and growth over time. For our purposes, the model has to be consistent with at least four stylised facts. Jones (2002), based on EIA (1999) summarises these for the US over the period 1950–1998. First, energy efficiency (GDP per unit of energy input) has improved at an annual rate of 1.4% on average. Second, per capita energy use has increased at an average annual rate of about 1%. Third, the share of energy cost in GDP has declined at an average annual rate of about 1%. Fourth, energy prices per unit of labour cost have declined (see also Nordhaus, 1992 and Simon, 1996). Needless to say, the trends for the period 1971–1980 are markedly different, with even faster improvements in the energy efficiency, falling per capita energy inputs, and a sharply rising energy cost share (from 2% in 1970 to 7% in 1980). In Table 1 and Fig. 1 and Fig. 2, we present figures based on own calculations for the US, Japan, and three large European economies.1 The trends after 1969 are similar to those of the US.In our model, per capita energy evolves exogenously and ongoing technical change explains the steady decline in energy intensity, energy share, and price of energy relative to wages. Labour and energy inputs enter the production function symmetrically as gross complements. Energy and labour are each combined with specific complementary intermediate inputs, to be interpreted as capital. Monopolistic firms supply these intermediate goods and have the opportunity to invest in improved quality of the goods. In the transition to the steady state, the effective supply of energy, corrected for these quality improvements, grows faster than the effective supply of labour, which results in a gradual decline in the share of energy. We study the effects of energy conservation by exogenously reducing either the level or the growth rate of energy inputs in the model. Energy becomes scarcer and producers are willing to pay higher prices for energy services. The returns to investment in quality improvements of energy-related intermediates rise relatively to labour-related innovations. This spurs energy-related innovation, possibly at the cost of labour-related innovation. In the new equilibrium, the direction of innovation has shifted to energy and rates of return are equalised over the two types of innovation projects. If this new common rate of return has increased, the aggregate rate of innovation is stimulated as well. We show that this may happen if innovators in energy-related sectors are better able to appropriate the social returns to innovation than those in other sectors. We find that energy conservation reduces output levels both in the short and long run. These lower levels are typically associated with higher short-run per capita growth rates. Long-run growth rates are not affected by a permanent change in the level of energy input, but fall if the growth rate of energy inputs is permanently reduced. Induced technical change may result in smaller drops in output than when technological change is exogenous. Our analysis is related to the literature on environmental policy and technology (Goulder and Mathai, 2000), and the literature on the environment and growth (Bovenberg and Smulders, 1995 and Smulders, 2000). While the former typically concentrates on how environmental policy induces technological change and learning in particular directions or sectors in a partial analysis, the latter takes a general-equilibrium perspective with only one type of research. Goulder and Schneider (1999) and Buonanno et al. (2001) combine the two approaches in a calibrated model in which perfect competition prevails in all markets. We aim at integrating the induced technology and growth perspective, without giving up the analytical tractability and micro-foundations of the endogenous growth models. Our model builds on growth theory. Neoclassical resource-and-growth models assume exogenous technology but concentrate on endogenous depletion of non-renewable resources (see the surveys by Dasgupta and Heal, 1979 and Withagen, 1991). We complement this approach by focusing on endogenous technology, with exogenous energy supply.2 Other models of endogenous growth and energy use have focussed on a single type of innovation and Cobb–Douglas production functions (Aghion and Howitt, 1998, Chapter 5; Grimaud and Rouge, 2001 and Van Zon and Yetkiner, 2003). We complement this literature by allowing for both labour-augmenting and energy-augmenting technological change, and elasticities of substitution below unity (that is, labour and energy are gross complements).3 Our modelling of production and innovation partly follows Acemoglu, 1998 and Acemoglu, 2001 and Kiley (1999), who develop a framework to analyse the forces that shape the direction of technical change towards particular factors of production. We are interested in whether a change in the direction of technical change may accelerate aggregate growth, rather than in explaining the direction itself. We therefore explicitly relate forces that direct technological change to forces that shape the overall productivity of innovation. Our model deviates from Acemoglu’s model in some important respects. First, innovation is undertaken in-house in our model (in the spirit of Smulders and van de Klundert, 1995), while Acemoglu’s model relies on creative destruction (as in Aghion and Howitt, 1992) and Kiley’s model relies on labour division and variety expanding (as in Romer, 1990). In this respect, our approach is complementary to Kiley and Acemoglu by studying a third mode of R&D driven economic growth. Second, while in Acemoglu, 1998 and Acemoglu, 2001 and Kiley (1999), the relative supply of primary factors is stationary, we allow for steady increases in the supply of energy relative to labour supply. Third, we stress that technological change may be biased because of differences in appropriability conditions for different investment projects (cf. Nahuis and Smulders, 2002). Our analysis is divided in three stages to clearly disentangle the effects of (i) the presence of technical change per se, (ii) the endogeneity of the bias of technology (induced technical change), and (iii) the endogeneity of the rate of technical change. In Section 2, we consider the production side of the economy and take technology as exogenous. We illustrate how exogenous reductions in energy use affect the aggregate growth rate for given technological change. In Section 3, we introduce induced technological change by modelling how firms change the type of innovation projects if energy supply changes and the total research budget is held constant. In Section 4, the total amount of innovation in the economy may respond to rates of return to innovation. Section 5 concludes

نتیجه گیری انگلیسی

In our model, per capita energy evolves exogenously and ongoing technical change explains the steady decline in energy intensity, energy share, and price of energy relative to wages. Labour and energy inputs enter the production function symmetrically as gross complements. Energy and labour are each combined with specific complementary intermediate inputs, to be interpreted as capital. Monopolistic firms supply these intermediate goods and have the opportunity to invest in improved quality of the goods. In the transition to the steady state, the effective supply of energy, corrected for these quality improvements, grows faster than the effective supply of labour, which results in a gradual decline in the share of energy. We study the effects of energy conservation by exogenously reducing either the level or the growth rate of energy inputs in the model. Energy becomes scarcer and producers are willing to pay higher prices for energy services. The returns to investment in quality improvements of energy-related intermediates rise relatively to labour-related innovations. This spurs energy-related innovation, possibly at the cost of labour-related innovation. In the new equilibrium, the direction of innovation has shifted to energy and rates of return are equalised over the two types of innovation projects. If this new common rate of return has increased, the aggregate rate of innovation is stimulated as well. We show that this may happen if innovators in energy-related sectors are better able to appropriate the social returns to innovation than those in other sectors. We find that energy conservation reduces output levels both in the short and long run. These lower levels are typically associated with higher short-run per capita growth rates. Long-run growth rates are not affected by a permanent change in the level of energy input, but fall if the growth rate of energy inputs is permanently reduced. Induced technical change may result in smaller drops in output than when technological change is exogenous. Our analysis is related to the literature on environmental policy and technology (Goulder and Mathai, 2000), and the literature on the environment and growth (Bovenberg and Smulders, 1995 and Smulders, 2000). While the former typically concentrates on how environmental policy induces technological change and learning in particular directions or sectors in a partial analysis, the latter takes a general-equilibrium perspective with only one type of research. Goulder and Schneider (1999) and Buonanno et al. (2001) combine the two approaches in a calibrated model in which perfect competition prevails in all markets. We aim at integrating the induced technology and growth perspective, without giving up the analytical tractability and micro-foundations of the endogenous growth models. Our model builds on growth theory. Neoclassical resource-and-growth models assume exogenous technology but concentrate on endogenous depletion of non-renewable resources (see the surveys by Dasgupta and Heal, 1979 and Withagen, 1991). We complement this approach by focusing on endogenous technology, with exogenous energy supply.2 Other models of endogenous growth and energy use have focussed on a single type of innovation and Cobb–Douglas production functions (Aghion and Howitt, 1998, Chapter 5; Grimaud and Rouge, 2001 and Van Zon and Yetkiner, 2003). We complement this literature by allowing for both labour-augmenting and energy-augmenting technological change, and elasticities of substitution below unity (that is, labour and energy are gross complements).3 Our modelling of production and innovation partly follows Acemoglu, 1998 and Acemoglu, 2001 and Kiley (1999), who develop a framework to analyse the forces that shape the direction of technical change towards particular factors of production. We are interested in whether a change in the direction of technical change may accelerate aggregate growth, rather than in explaining the direction itself. We therefore explicitly relate forces that direct technological change to forces that shape the overall productivity of innovation. Our model deviates from Acemoglu’s model in some important respects. First, innovation is undertaken in-house in our model (in the spirit of Smulders and van de Klundert, 1995), while Acemoglu’s model relies on creative destruction (as in Aghion and Howitt, 1992) and Kiley’s model relies on labour division and variety expanding (as in Romer, 1990). In this respect, our approach is complementary to Kiley and Acemoglu by studying a third mode of R&D driven economic growth. Second, while in Acemoglu, 1998 and Acemoglu, 2001 and Kiley (1999), the relative supply of primary factors is stationary, we allow for steady increases in the supply of energy relative to labour supply. Third, we stress that technological change may be biased because of differences in appropriability conditions for different investment projects (cf. Nahuis and Smulders, 2002). Our analysis is divided in three stages to clearly disentangle the effects of (i) the presence of technical change per se, (ii) the endogeneity of the bias of technology (induced technical change), and (iii) the endogeneity of the rate of technical change. In Section 2, we consider the production side of the economy and take technology as exogenous. We illustrate how exogenous reductions in energy use affect the aggregate growth rate for given technological change. In Section 3, we introduce induced technological change by modelling how firms change the type of innovation projects if energy supply changes and the total research budget is held constant. In Section 4, the total amount of innovation in the economy may respond to rates of return to innovation. Section 5 concludes

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