the expansion of modern agriculture and global biodiversity decline an integrated assessment the world is banking on a major increase in food production if the dietary needs and food preferences of an increasing and increasingly rich population are to be met this requires the further expansion of modern agriculture but modern agriculture rests on a small number of highly productive crops and its expansion has led to a significant loss of global biodiversity ecologists have shown that biodiversity loss results in lower plant productivity while agricultural economists have linked biodiversity loss on farms with increasing variability of crop yields and sometimes lower mean yields in this paper we consider the macro economic consequences of the continued expansion of particular forms of intensive modern agriculture with a focus on how the loss of biodiversity affects food production we employ a quantitative structurally estimated model of the global economy which jointly determines economic growth population and food demand agricultural innovations and land conversion we show that even small effects of agricultural expansion on productivity via biodiversity loss might be sufficient to warrant a moratorium on further land conversion

allocative inefficiency and the capital energy controversy abstract the purpose of the paper is to estimate a system of input demands for greek manufacturing deviating from the standard practice of assuming strict cost minimization the study allows for the presence of price distortions and allocative inefficiency in the decision process this assumption affects parameter estimates and estimated elasticities materially and throws new light on the capital energy controversy in greek manufacturing

general linear formulations of stochastic dominance criteria abstract we develop and implement linear formulations of general n th order stochastic dominance criteria for discrete probability distributions our approach is based on a piece wise polynomial representation of utility and its derivatives and can be implemented by solving a relatively small system of linear inequalities this approach allows for comparing a given prospect with a discrete set of alternative prospects as well as for comparison with a polyhedral set of linear combinations of prospects we also derive a linear dual formulation in terms of lower partial moments and co lower partial moments an empirical application to historical stock market data suggests that the passive stock market portfolio is highly inefficient relative to actively managed portfolios for all investment horizons and for nearly all investors the results also illustrate that the mean variance rule and second order stochastic dominance rule may not detect market portfolio inefficiency because of non trivial violations of non satiation and prudence

a test for subadditivity of the cost function with an application to the bell system stable url http links jstor org sici sici 0002 8282 28198409 2974 3a4 3c615 3aatfsot 3e2 0 co 3b2 rthe american economic review is currently published by american economic association your use of the jstor archive indicates your acceptance of jstor s terms and conditions of use available athttp www jstor org about terms html jstor s terms and conditions of use provides in part that unless you have obtainedprior permission you may not download an entire issue of a journal or multiple copies of articles and you may use content inthe jstor archive only for your personal non commercial use please contact the publisher regarding any further use of this work publisher contact information may be obtained athttp www jstor org journals aea html each copy of any part of a jstor transmission must contain the same copyright notice that appears on the screen or printedpage of such transmission the jstor archive is a trusted digital repository providing for long term preservation and access to leading academicjournals and scholarly literature from around the world the archive is supported by libraries scholarly societies publishers and foundations it is an initiative of jstor a not for profit organization with a mission to help the scholarly community takeadvantage of advances in technology for more information regarding jstor please contact support jstor org http www jstor orgmon jul 2 16 52 19 2007

energy taxes and endogenous technological change abstract this paper studies the effects of a tax on energy use in a growth model where market structure is endogenous and jointly determined with the rate of technological change because this economy does not exhibit the scale effect a positive relation between tfp growth and aggregate r d the tax has no effect on the steady state growth rate it has however important transitional effects that give rise to surprising results specifically under the plausible assumption that energy demand is inelastic there may exist a hump shaped relation between the energy tax and welfare this shape stems from the fact that the reallocation of resources from energy production to manufacturing triggers a temporary acceleration of tfp growth that generates a shaped time profile of consumption if endogenous technological change raises consumption sufficiently fast and by a sufficient amount in the long run and households are sufficiently patient the tax raises welfare despite the fact that in line with standard intuition it lowers consumption in the short run

population concentration urbanization and demographic transition abstract this paper investigates how urbanization and demographic transition interrelate with each other via merits agglomeration economies and demerits congestion diseconomies of population concentration it reveals the mechanism by which agglomeration economies and congestion diseconomies affect the fertility rate furthermore analysis also shows that by assuming declines in infant and child mortality rate the model developed in this paper can replicate the following well known historical patterns i advances in urbanization ii rises in the wage rate iii declines in fertility and iv rises followed by declines in the population growth rate the inverted u shaped demographic transition

the effects of shifts in a return distribution on optimal portfolios when the distribution of the returns of a risky asset undergoes a stochastically dominating shift a risk averse investor may not necessarily increase the investment in that asset this paper provides restrictions on the investor s utility function that are necessary and sufficient for a dominating shift to bring about no decrease in the investment in the respective asset if there are two risky assets in the portfolio these conditions are also necessary if there are n 2 assets and are necessary and sufficient if the utility function exhibits constant absolute risk aversion copyright 1990 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

almost marginal conditional stochastic dominance marginal conditional stochastic dominance mcsd developed by shalit and yitzhaki 1994 gives the conditions under which all risk averse individuals prefer to increase the share of one risky asset over another in a given portfolio in this paper we extend this concept to provide conditions under which most and not all risk averse investors behave in this way instead of stochastic dominance rules almost stochastic dominance is used to assess the superiority of one asset over another in a given portfolio switching from mcsd to almost mcsd amcsd helps to reconcile common practices in asset allocation and the decision rules supporting stochastic dominance relations a financial application is further provided to demonstrate that using amcsd can indeed improve investment efficiency

global population growth technology and malthusian constraints a quantitative growth theoretic perspective we structurally estimate a two sector schumpeterian growth model with endogenous population and finite land reserves to study the long run evolution of global population technological progress and the demand for food the estimated model closely replicates trajectories for world population gdp sectoral productivity growth and crop land area from 1960 to 2010 projections from 2010 onwards show a slowdown of technological progress and because it is a key determinant of fertility costs significant population growth by 2100 global population reaches 12 4 billion and agricultural production doubles but the land constraint does not bind because of capital investment and technological progress

competition and allocative efficiency the case of the u s telephone industry this study investigates the effect of competition on the productive efficiency of the u s telephone industry taking into account the fact that the industry was subject to rate of return regulation it is shown that competition induces the incumbents to use capital inputs closer to the unconstrained optima thereby reducing the allocative inefficiency caused by the averch johnson effect this effect is in addition to the usual technical efficiency improvement induced by competition empirical results based on annual data for the u s telephone industry for the 1951 90 period suggested that competition improved the allocative efficiency of the incumbent firms which had been under a rate of return regulation until 1989 copyright 1995 by mit press

the population problem theory and evidence this study is concerned with the relationships among population growth poverty and environmental degradation with particular focus on the situation in developing countries the author rejects the concept of a general theory of fertility behavior in favor of an interpretation of these relationships which might be applicable to certain situations in the poorest parts of the indian subcontinent and sub saharan africa such situations include unacceptable risks of maternal death for poor illiterate women and a condemnation to extreme poverty in conditions of the deterioration of local resources and of the environment the author concludes that population growth rates are too high in certain specific areas and that an appropriate policy reaction to such conditions would be to try to change the options that men and women face so that their reasoned choice would be to lower their fertility

scarcity growth and r d abstract the limits to economic growth due to resource scarcity can be alleviated only by the development of backstop substitutes this paper combines resource based economic growth with r d to reduce the cost of backstop technologies characterizing the entire dynamics of optimal growth and r d processes we find that an economy s growth prospects depend on its type as determined by its production technology and learning ability and by its knowledge capital endowment a wide variety of growth patterns emerges ranging from cases in which an economy that without r d eventually stagnates converges to a steady state is diverted by r d onto a path of sustained growth to cases in which r d is not warranted resource scarcity is shown to encourage r d due to the increased reliance on the backstop technology

hartwick s rule and maximin paths when the exhaustible resource has an amenity value abstract this paper studies the maximin paths of the canonical dasgupta heal solow model when the stock of natural capital is a direct argument of well being besides consumption hartwick s rule then appears as an efficient tool to characterize solutions in a variety of settings we start with the case without technical progress we obtain an explicit solution of the maximin problem in the case where production and utility are cobb douglas when the utility function is ces with a low elasticity of substitution between consumption and natural capital we show that it is optimal to preserve forever a critical level of natural capital determined endogeneously we then study how technical progress affects the optimal maximin paths in the cobb douglas utility case on the long run path of the economy capital production and consumption grow at a common constant rate while the resource stock decreases at a constant rate and is therefore completely depleted in the very long run a higher amenity value of the resource stock leads to faster economic growth but to a lower long run rate of depletion we then develop a complete analysis of the dynamics of the maximin problem when the sole source of well being is consumption and provide a numerical resolution of the model with resource amenity the economy consumes produces and invests less in the short run if the resource has an amenity value than if it does not whereas it is the contrary in the medium and long runs however and without surprise the resource stock remains for ever higher with resource amenity than without

constant savings rates and quasi arithmetic population growth under exhaustible resource constraints in the dasgupta heal solow stiglitz dhss model of capital accumulation and resource depletion we show the following equivalence if an efficient path has constant gross and net of population growth savings rates then population growth must be quasi arithmetic and the path is a maximin or a classical utilitarian optimum conversely if a path is optimal according to maximin or classical utilitarianism with constant elasticity of marginal utility under quasi arithmetic population growth then the gross and net of population growth savings rates converge asymptotically to constants

malthus in the light of climate change abstract to reconsider the malthusian predictions of natural limits to economic development the paper develops a multi sector growth model with exhaustible resource extraction investments in physical and knowledge capital climate change and endogenous fertility economic growth is driven by endogenous innovations which increase in the availability and productivity of research labour poor substitution of natural resources triggers sectoral change climate change is the result of polluting resource use which is like consumption and investments based on the intertemporal optimization of the households highlighting the importance of bounded resource supply and of rational extraction decisions i show that climate change is independent of population growth in steady state and there is no causal relationship between climate and population during transition to steady state the consumption per capita growth rate rises in the innovation rate and the output elasticities of labour and capital in the different sectors unlike climate policy population policy is not warranted it may be counterproductive because labour is crucial for the research sector

unnatural monopolies in local telephone we attempt to overcome the serious data problems of past telecommunications cost studies by focusing on local exchange carriers lecs with enough degrees offreedom to yield precise estimates our global subadditivity tests show that the cost function is definitely not subadditive the results suggest that the benefits to breaking up the monopoly outputs of existing lecs substantially outweigh the potential losses in efficiency they also support permitting entry and increasing competition in local exchange markets furthermore given the competitive nature of long distance service it is doubtful that the predivestiture bell system was a natural monopoly

human capital and economic development abstract this paper develops a general equilibrium model of fertility and human capital investment with young adult mortality because young adult mortality is negatively related to average young adult human capital human capital accumulation lowers mortality inducing demographic transition and industrial revolution data confirm that young adult mortality is related negatively to schooling and the rate of return to schooling and positively to fertility the data indicate a negative relationship between tfp growth and schooling accumulation the model fits the data on country populations per capita incomes human capital total fertility rates infant mortality life expectancy and conditional life expectancy

stochastic dominance and expected utility survey and analysis while stochastic dominance has been employed in various forms as early as 1932 it has only been since 1969 1970 that the notion has been developed and extensively employed in the area of economics finance agriculture statistics marketing and operations research in this survey the first second and third order stochastic dominance rules are discussed with an emphasis on the development in the area since the 1980s

a note on asset proportions stochastic dominance and the 50 rule in this note we analyze the composition of an optimal portfolio by considering the cumulative conditional expected outcome of two dependent assets we develop a conditional stochastic dominance relation and show that for any concave von neumann morgenstern utility function the proportion of wealth invested in the dominant asset will be greater than 50

the return of malthus resource constraints in an era of declining population growth abstract will natural resources comprise an important constraint on economic development in the 21st century we use a macroeconomic model mava to demonstrate the precise nature of this problem first we employ the model to demonstrate that resource constraints do not substantially limit future economic growth under parametric conditions prevailing in the period 1960 2010 second we examine the sorts of changed conditions that are unavoidable in the coming century and demonstrate that declining population growth and the increased dependency rates this implies is likely to result in increasingly important resource constraints ironically it is the decline in population growth rates and not the opposite that may occasion the return of malthusian constraints 1

the canonical classical model of political economy adam smith david ricardo thomas robert malthus and john stuart mill shared in common essentially one dynamic model of equilibrium growth and distribution when the limitation of land and natural resources is added to the model of karl marx he also ends up with this same canonical classical model in its present version the model is stripped down to its minimal essentials for brevity i employ modern mathematical tools but only to characterize in modern terms the relations that were actually common to all these writers the reader should of course be warned that any simple codification of the classical economists discursive writings must be an oversimplification in some of their passages they qualify what they have written elsewhere in some they provide negations and contradictions not a few of the stereotypes about the classical writers are to paraphrase voltaire myths agreedupon by later commentators distortions that both improve and libel the originals the relevant object of study for a modern scholar is the corpus of original texts and the commentaries on them the latter not being genuinely of less interest than the former once we have succeeded in telling them apart to the fascinating question of whether classical political economy does or can be made to offer an alternative paradigm in the sense of thomas kuhn 11 1962 to modern mainstream economics the present investigation provides an instructive answer so to speak within every classical economist there is to be discerned a modern economist trying to be born a ricardo or mill did not so much replace supply and demand by quite different mechanisms but rather sought to be able to say something significant and limiting about their properties quite in the same way that we moderns endeavor to do i describe and analyze here the basic classical model in its essential form

estimated substitution elasticities of a nested ces production function approach for germany this paper demonstrates an econometric estimation of substitution elasticities of a nested constant elasticity of substitution production function ces between capital energy and labour for the west german industry in the last few years ces production functions have become more important in economic modelling especially for applied general equilibrium models where ces production functions are an important building stone in the literature different results of estimated elasticities can be found this paper investigates three different approaches for nested ces production functions and their estimated substitution elasticities capital energy and labour are estimated as substitutes for the west german industry in the long run

global economic growth and agricultural land conversion under uncertain productivity improvements in agriculture we study how stochasticity in the evolution of agricultural productivity interacts with economic and population growth at the global level we use a two sector schumpeterian model of growth in which a manufacturing sector produces the traditional consumption good and an agricultural sector produces food to sustain contemporaneous population agriculture demands land as an input itself treated as a scarce form of capital in our model both population and sectoral technological progress are endogenously determined and key technological parameters of the model are structurally estimated using 1960 2010 data on world gdp population cropland and technological progress introducing random shocks to the evolution of total factor productivity in agriculture we show that uncertainty optimally requires more land to be converted into agricultural use as a hedge against production shortages and that it significantly affects both optimal consumption and population trajectories

demand for risky financial assets a portfolio analysis abstract demand for risky financial assets takes place in portfolio settings the common stochastic orders applied in economics fail to rank demand for assets in such situations even for risk averse investors therefore the evaluation of the relative desirability of risky financial assets requires the establishment of new orders we prove that if returns on risky assets are ordered by the monotone likelihood ratio order then dominating assets will be more desired by all investors with nondecreasing utility functions

telecommunications deregulation and subadditive costs are local telephone monopolies unnatural abstract in early 1996 congress passed the telecommunications law providing the foundation for the opening of regulated local telephone monopolies to competition one important premise for introducing competition into local telephone markets is that these markets are not or are no longer natural monopolies this paper reexamines the natural monopoly issue using a cost function that controls for firm heterogeneity our subadditivity tests suggest that local exchange carriers lecs costs are subadditive when there are controls for unobserved heterogeneity suggesting that local telephone markets are natural monopoly markets

a goal programming constrained regression review of the bell system breakup the recently implemented court decision to break up bell american telephone telegraph co to accord with u s anti trust laws represents a highly significant policy decision which is proving to be influential in other countries as well as the u s the telecommunication industry is of such size and importance that even relatively small economies that might be lost with bell s breakup as a natural monopoly could involve substantial welfare losses to consumers and producers studies commissioned by the u s justice department that approached this topic by econometric methods reported that the evidence failed to support the contention that bell was a natural monopoly here a goal programming constrained regression as developed in the management science literature uses the same functional form and the same data but nevertheless reverses the main findings of the econometric studies in every one of the 20 years covered this kind of difference in results obtained by two different methods of analysis poi

social criteria for evaluating population change an alternative to the blackorby donaldson criterion abstract an ethical objection is raised against the blackorby donaldson criterion of optimum population maximizing the sum total of utilities in excess of some critical level since it may disprefer a social state with more people and with more worthwhile lives however the criterion may serve as a practicably reasonable compromise between maximizing total and average utility nevertheless an alternative compromise the maximization of number dampened total utility is proposed that is free from the above objection

changing world prices women s wages and the fertility transition sweden 1860 1910 this time series analysis examines during 1860 1910 the impact of changes in local prices of agricultural commodities on wages among men and women in sweden and the impact of changes in wages on fertility decline child mortality urbanization and improved social conditions linear ordinary least squares models are set up to determine whether demand induced increases in womens wages relative to mens are significant factors in explaining swedish total fertility rates data are obtained from 25 counties and the city of stockholm among pooled observations for six time periods during 1860 64 and 1910 14 this period is marked by a total fertility decline of 28 a marital fertility decline of 26 and a child mortality decline of 52 explanatory variables are the relative prices of main agricultural outputs employment outside of agriculture the proportion of urban population and the child mortality rate findings indicate a significant relationship between child mortality and total fertility and specific fertility rates among women aged 20 39 years a doubling of the male real wage rate was significantly associated with earlier marriage higher birth rates among women aged 15 29 years and lower birth rates among women aged 35 49 years the ratio of male wages to female wages was associated with a decline in birth rates at all ages with the exception of teenagers 66 of fertility increase was due to declines in child mortality but this increase was counterbalanced by fertility decline among older women child mortality and urbanization depressed marital fertility male wages increased the proportion married a 10 increase in the male female wage rate was associated with a 25 reduction in the total fertility rate another 25 increase in the male female wage rate was associated with a 50 reduction in child mortality it is concluded that the value of womens time had a key impact on the swedish fertility transition

inequality and growth why differential fertility matters we argue that inequality and growth are linked through differential fertility and the accumulation of human capital we build an overlapping generations model in which dynasties differ in their initial endowment with human capital growth the income distribution and fertility are endogenous due to a quantiy quality tradeoff families with less human capital decide to have more children and invest less in education when initial inequality is high large fertility differentials lower the growth rate of average human capital since poor families who invest little in education make up a large fraction of the population in the next generation a calibrated model shows that this fertility differential effect is quantitatively important we also provide empirical evidence to confirm the links between inequality differential fertility and growth suggested by the model

population growth and natural resource scarcity long run development under seemingly unfavorable conditions in this paper i consider an economy that is constrained by the use of natural resources and driven by knowledge accumulation resources are essential inputs in all sectors i show that population growth and poor input substitution are not detrimental but on the contrary are even necessary to obtain a sustainable consumption level i find a general rule to define the conditions for a constant innovation rate the rule does not apply to capital but to labor growth which is the crucial input in research furthermore the rule relates to the sectoral structure of the economy and to demographic transition the results continue to hold with a backstop technology and are extended for the case of minimum resource constraints

asset proportions in optimal portfolios the paper is concerned with conditions under which the proportion of a given asset in the optimal portfolio of a risk averse agent is at least as large as some given proportion the paper provides a condition that is necessary and sufficient for such a result to hold the analysis is then confined to portfolios in which the distributions of assets differ by either a first degree stochastic dominance shift or by a mean preserving shift examples are provided to show that under some conditions a risk averter may invest a smaller proportion of his wealth in the dominating asset than in the dominated asset the paper then provides conditions that are necessary and sufficient for a risk averter to invest more in the dominating asset the question of whether risk averse agents should or should not choose diversified portfolios as opposed to specialized ones has been analysed quite extensively in the literature examples of such works are samuelson 1967 brumelle 1974 hadar and russell 1974 russell and seo 1979 hadar and seo 1980 and macminn 1984 what has not been examined at all except for very special cases is the question of the optimal proportions of the various assets in a diversified portfolio in this paper we present conditions which imply that the optimal amount invested in a particular asset is at least as large as some given proportion of the available fund in the case of two asset portfolios one may especially want to know which of the two assets represents more than half the investible fund indeed we find it convenient to start the analysis with the two asset case while the extension to n asset protfolios is essentially straightfoward it is presented in a subsequent section focusing first on the two asset case will make it easier for the reader to see the main logical steps in the proofs of the theorems some of our analysis is facilitated by the use of a particular subset of risk averters this subset has the property that if its members behave in a particular way then all risk averters behave in that way we refer to such a subset as a representative set of all risk averters 2 the usefulness of the representative set derives from the fact that its members have utility functions of a very simple form consisting of two linear pieces and its applicability to the problems on hand derives from the fact that any concave function can be approximated by a linear combination of members of the representative set in the next section we present some formal results demonstrating the equivalence of unanimity among members of the representative set and unanimity among all risk averters in certain types of choice situations these theorems are then used in section 3 in which we present the results about optimal asset proportions

making inefficient market indices efficient this paper uses the concept of marginal conditional stochastic dominance and a generalization of the 50 portfolio rule to develop a tractable and parsimonious methodology for constructing a second degree stochastic dominance ssd efficient portfolio from a given inefficient index because the ssd approach considers the entire probability distributions of asset returns the resulting portfolios are efficient with respect to all risk averse utility maximizing investors regardless of the form of their utility functions or the distributions of asset returns