optimal growth with many consumers abstract a method is described for constructing all pareto optimal allocations for a dynamic economy with many heterogeneous consumers under certainty in which both the technology and consumer preferences are recursive but preferences need not be additively separable over time optimal perfect foresight competitive equilibrium allocations are obtained through the study of a dynamic program for an economy with one consumption good sufficient conditions are given for the existence of a unique interior stationary distribution of consumption and wealth for a two person exchange economy sufficient conditions are given for the global asymptotic stability of the unique interior stationary point

interpreting comovements in the trade balance and the terms of trade abstract i examine the relation between the trade balance and the terms of trade in a two country dynamic stochastic exchange economy with complete markets along an equilibrium path for this economy the relation is governed by the substitutability between foreign and domestic goods i find in contrast to non stochastic analyses of the harberger laursen metzler effect that a positive association does not require persistent shocks or non constant rates of time preference this contrast highlights the role played by the structure of asset markets complete and otherwise in generating equilibrium comovements

weakly non separable preferences and the harberger laursen metzler effect we examine the current account effect of a terms of trade deterioration for a small country model incorporating weakly non separable preferences a la shi 1994 under endogenous time preference this enables us to emphasize a welfare change as an important determinant of the current account even with increasing marginal impatience the harberger laursen metzler effect occurs if consumers preference toward imports is sufficiently wealth enhanced in that case a terms of trade deterioration must reduce steady state welfare to shift preference away from imports to exports several empirical implications are also derived jel classification f41 f32 preferences faiblement nonseparables et l effet de harberger laursen metzler l auteur examine l effet sur le compte courant d une deterioration des termes d echange dans un modele d un petit pays quand les preferences sont faiblement nonseparables a la shi 1994 et que la preference temporelle est endogene cela permet de souligner qu un changement dans le niveau de bien etre est un determinant important du compte courant contrairement a ce qu on trouve dans la litterature specialisee meme quand on postule une impatience marginale croissante l effet harberger laursen metzler se produit si la preference des consommateurs pour les importations est suffisamment dependante du niveau de richesse dans ce cas la une deterioration des termes d echange doit reduire le niveau de bien etre en regime permanent de maniere a deplacer les preferences des importations vers les exportations on deduit certaines implications empiriques de ces resultats

redistributive taxation in a simple perfect foresight model abstract we investigate the redistributive potential of capital taxation in an intertemporal maximizing model of capital formation first even unanticipated redistributive capital taxation is severely limited in its effectiveness since it depresses wages second under any convergent redistributive tax policy which maximizes a paretian social objective the capital income tax will converge to zero independent of the factor supply elasticities these results are independent of workers holdings of capital

the terms of trade and the current account the harberger laursen metzler effect the paper examines the effect of terms of trade changes on a small country s spending and current account assuming optimizing behavior in an intertemporal framework with perfect international capital mobility a temporary future terms of trade deterioration implies a deterioration improvement of the trade balance whereas a permanent terms of trade deterioration has an ambiguous effect depending on the rate of time preference nominal and real variables are considered via exact price indexes two periods and an infinite horizon are examined

increasing returns and increasing rates of growth romer 1986b documented that industrial economies have tended to have growth rates that increase over time having explained why the aggregate growth models of ramsey 1928 cass 1965 and koopmans 1965 fail to account for this observation romer proposed an alternative view of long run prospects for growth combining three elements externalities increasing returns in the production of output and decreasing returns in the production of new knowledge he constructed an equilibrium model of growth in his infinite horizon continuous time analysis qualitative conclusions were reached using the geometry of the phase plane no examples with an explicit dynamic solution were given the present paper provides a fully worked out example that fills this gap and that can serve as a confirmation of romer s claim that monotonically increasing growth rates for the capital stock and for consumption can arise in the framework he specified this paper also presents an example that can generate increasing growth rates without imposing some of the restrictions essential to romer s model those restrictions are not appealing on economic grounds and were added to his paper purely for technical reasons any infinite horizon model with increasing returns to scale must impose some restrictions to ensure the existence of both a social optimum and a competitive equilibrium otherwise the discounted sum of utility could go to infinity romer 1986b used a production function of the form f k k akvkw with v y 1 where k is the capital stock at the level of the firm and k is aggregate capital the

a simple dynamic general equilibrium model abstract we analyse a single sector economy with h 1 infinitely lived agents that operate in a continuous time framework utility functions are recursive but not additive both efficient and perfect foresight competitive equilibrium allocations are considered the existence and stability of such allocations are investigated locally i e in a neighbourhood of steady state allocations the model is shown to be useful for explaining the distribution of wealth and consumption across agents and for analysing the way in which wealth redistribution can affect the dynamics of aggregate economic variables

impatience and long run growth abstract this contribution is concerned with the possibility of a perpetual growth path at increasing rates in a nonconvex optimal growth model with endogenous discounting sufficient conditions for the existence of this path can be established when the economy is populated by agents whose impatience does not increase too much along the course of a consumption path in the opposite case the dynamical system is asymptotically described by a steady state however this steady state position need not be uniquely defined saddlepoint equilibria and locally oscillating unstable equilibria may alternate in spite of increasingly impatient agents along the growth process it remains optimal for a government to subsidize the competitive economy under a razor edge assumption on impatience a growing planning solution may coexist with a stationary competitive solution

the global stability of efficient intertemporal allocations this paper describes a continuous time model of an economy with finitely many infinitely lived consumers and a finite number of capital goods two objectives are achieved first recursive nonadditive utility functionals are formulated and analyzed second these preference functionals are applied to analyze the nature of efficient allocations in a dynamic economy two classes of global turnpike propositions are proven which provide the basis for a model of the long run distribution of wealth these propositions also provide new perspective regarding existing stability literature based on additive utilities copyright 1987 by the econometric society

the rate of time preference and dynamic economic analysis strong restrictions on the structure of preferences are a central feature in the received theory of intertemporal allocation in fact most of the modern literature concerned with capital theoretic problems represents preferences by a functional in which an additive utility function is discounted by a constant rate of time preference this specification is attractive because it is analytically tractable in dynamic models and it clearly delineates how tastes and opportunities interact to determine an economy s household s paths of consumption and capital formation however its rigid structure constancy of time preference severely limits the conclusions and explanatory power of the corresponding models this paper considers a class of utility functionals in continuous time which have the appealing feature that the rate of time preference depends systematically on an index of aggregate future consumption the more flexible structure embodied in these functionals leads to important generalizations and

weakly nonseparable preferences and distortionary taxes in a small open economy this paper examines the dynamic effects of distortionary taxes in a small open economy the employed utility function implies both endogenous rates of time preference and a tractable form of weak nonseparability between consumption and leisure weak nonseparability induces novel long run welfare and wealth effects of taxes and generates very different current account movements endogenous rates of time preference facilitate the examination of a tax on international borrowing and lending copyright 1994 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

optimal growth with decreasing marginal impatience abstract this paper analyses the long run dynamics of a continuous time infinite horizon optimal growth model with identical households where the households rate of time preference is endogenously determined however unlike the existing literature we assume that households have decreasing marginal impatience i e the instantaneous discount rate is negatively related to the current consumption with this assumption we analyse the stability and uniqueness of the long run equilibrium we show that contrary to the general belief a negative relationship between the instantaneous discount rate and the household s current consumption does not necessarily result in instability of the dynamic system however even a stable system may be characterized by multiple equilibria so that the initial condition becomes important in determining the long run behaviour of the economy we derive a set of sufficient conditions for stability and uniqueness in this context

wearable technologies and health behaviors new data and new methods to understand population health we study a randomized control trial in a large employer population of access to wearable technologies and the associated planning and monitoring tools on improved health behaviors sleep and exercise both itt and iv estimates based on actual plan enrollment for the treatment group suggest statistically significant but economically small changes in behavior after three months we then implement machine learning based models to assess treatment effect heterogeneity we find little evidence for heterogeneous treatment effects base on observables we also present detailed data on sleep patterns underscoring the value of this new data source to researchers

capital accumulation and the current account in a two country model abstract this paper examines the joint determination of international debt and capital accumulation in a two country model national rates of time preference are endogenous adjusting along an optimal path to come into equality with one another in the steady state the characteristics of short run current account dynamics are crucially linked to world capital accumulation and to a country s long run net external asset position steady state creditor countries tend to have current account surpluses during episodes of world output growth and vice versa for debtor countries this gives rise to possible non monotonic adjustment in the current account and consumption

intertemporal dependence impatience and dynamics abstract this paper develops simple geometric methods for analyzing consumer behavior under recursive but intertemporally dependent tastes since the preferences studied need not be time additive they allow the marginal utility of consumption on a given date to vary with consumption on other dates intertemporal dependence is induced by the presence of a variable individual rate of time preference the optimal consumption responses to transitory and anticipated changes in incomes and interest rates are easily derived and are similar in many respects to the responses implied by the standard constant time preference model intuitive explanations of the first order conditions describing optimal paths are provided

balanced budget consumption taxes and aggregate stability in a small open economy in a small open economy facing a perfect world capital market this paper shows that if the government follows a balanced budget fiscal policy based on endogenous consumption tax rates then the steady state is saddle path stable and hence beliefs driven aggregate instability can be ruled out this result is in contrast to those obtained in some closed economy models and it suggests that unrestricted world capital mobility can help stabilize the economy under the balanced budget fiscal policy based on consumption taxation

habit persistence and the harberger laursen metzler effect in an infinite horizon model abstract the habit persistence model of ryder and heal is used to examine the harberger laursen metzler h l m effect our results are in contrast to the general view in the literature that the stability requirements preclude the h l m effect in an infinite horizon model we show that if the marginal utility of real consumption is strongly increasing in the habitual standard of living then the h l m effect holds and a terms of trade deterioration reduces savings however if the marginal utility of real consumption is not sufficiently strongly increasing or is decreasing in the habitual standard then the h l m effect is overturned

endogenous discounting via wealth twin peaks and the role of technology we endogenize the discount rate via wealth and provide evidence that wealth affects the discount rate negatively we give a necessary and sufficient condition for endogenous discounting to lead to the twin peaks of economic growth and show that improvements in technology help avoid them

impatience and equilibrium indeterminacy abstract this paper extends the neoclassical one sector optimal growth model by postulating that individual agents time preference impatience depends on the economy wide average consumption and average income which are social factors taken as external by individual agents the paper shows that with the socially determined individual time preference local equilibrium indeterminacy can arise moreover local indeterminacy can also be associated with global indeterminacy in many cases the results hold in models with bounded and unbounded growth

hyperbolic discounting and endogenous growth this paper provides the closed form solution for the standard model of endogenous growth when consumers have present biased preferences and make time inconsistent savings plans which they revise continuously it is shown that long run growth is not necessarily lower under present biased preferences in fact a strong equivalence result holds if hyperbolic discounting provides the same present value of a constant infinite income stream as standard exponential discounting then the equilibrium rate of economic growth is also the same under both discounting methods in this sense present bias preferences are harmless for economic growth

patience and prosperity abstract this paper introduces wealth dependent time preference into a simple model of endogenous growth the model generates adjustment dynamics in line with the historical facts on savings and economic growth in europe from the high middle ages to today along a virtuous cycle of development more wealth leads to more patience which leads to more savings and further increasing wealth savings rates and income growth rates are thus jointly increasing during the process of development until they converge towards constants along a balanced growth path during the transition to modern growth an economy in which the association of wealth and patience is stronger overtakes an otherwise identical economy and generates temporarily diverging growth rates