A note on external habits and efficiency in the AK model

This paper examines the implications for equilibrium efficiency of alternative formulations of habit formation in the AK model with external habits. Agent’s utility depends on how her current consumption compares to a reference consumption level—the habits stock—determined by average past consumption in the economy. We first prove that perfect substitutability between consumption and habits along the equilibrium path is necessary and sufficient for efficiency. Then, we prove that the competitive equilibrium is efficient if and only if habits enter utility in a subtractive form.     

Renewable Resource Use and Nonseparable Amenity Benefits

We incorporate amenity benefits into an overlapping generations model with a renewable resource as a factor of production, source of amenity benefits and store of value. Unlike the conventional renewable resource problems studied under the assumption of additive consumption and amenity benefits, we let amenity benefits affect the utility of consumers in a nonseparable fashion. We examine the role that weights given to consumption and amenities have for harvesting and the resource stock. We characterize dynamics and stability of steady state equilibria with a logistic resource growth function. We demonstrate in parametric and numerical models that the weights given to consumption and amenities in the utility function matter substantially for the steady state equilibrium stock and its stability and dynamics. Both conventional saddle point equilibria and indeterminacy with infinite number of equilibria and saddle-node bifurcation is possible depending on the weights given to consumption and amenities. In addition, we show that for each inefficient equilibrium stock, there is a unique subsidy rate that can move the economy from an inefficient equilibrium to an efficient one. The presence of indeterminacy provides a challenge to resource policies, because the system becomes unpredictable. Therefore, expectations and market psychology may play an important role in resource utilization and provision of amenities.     

WELFARE IMPLICATIONS OF THE INTERACTION BETWEEN HABITS AND CONSUMPTION EXTERNALITIES*

We analyze the welfare properties of the equilibrium path of a growth model where both habits and consumption externalities affect the utility of consumers. Our analysis highlights the crucial role played by complementarities between externalities and habits in order to generate an inefficient dynamic equilibrium. In particular, we show that the competitive equilibrium is inefficient when consumption externalities and habit‐adjusted consumption are not perfect substitutes.     

The significance of Penrose's theory for the development of economics

Adam Smith identified the division of labour as the prime sourceof growth, through the generation of differentiated knowledge;the co-ordination problem was a consequence of this causal sequence.But Jevons, Walras, and their successors isolated co-ordinationfrom the growth of knowledge, and replaced causal sequenceswith formal proofs, despite Marshall's efforts to preserve Smith'stheoretical system. Penrose reinvented the Smith-Marshall analysisof the growth of knowledge, centred on the firm, but explicitlyendorsed the separation. Nevertheless her theory may permita more convincing treatment of the co-ordination of differentiatedknowledge than current models of rational choice equilibrium.     

Drèze equilibria and welfare maxima

We present an example of a production economy with incomplete markets, von Neumann–Morgenstern utility functions, and a unique Drèze equilibrium in order to illustrate and explain the following phenomenon. There exists a transfer scheme such that every shareholder’s utility after transfers and share adjustments increases the more the firm deviates from the Drèze equilibrium. However, shareholders’ welfare decreases the further the firm departs from the Drèze equilibrium. Shareholders’ welfare is defined as the sum of their utilities where every utility function is normalized such that the marginal utility of today’s consumption equals 1 at the Drèze equilibrium.     

On the stability of the constant relative risk aversion (CRRA) utility under high degrees of uncertainty

Growth models under uncertainty and constant relative risk aversion (CRRA) utility are fragile in explaining consumers’ choice, as equilibrium consumption is dependent on distributional assumptions. We show that, under semi-nonparametric distributions, general equilibrium models are stable, as the existence of expected utility is guaranteed.     

Adaptive behavior and the existence of Weizsäcker's long-run indifference curves

Suppose that past consumptions of the first r commodities (r < n) influence present consumption. Then, the long-run demand function to which demand converges maximizes the equilibrium short-run utility function only under very restrictive conditions. The long-run demand functions can be rationalized by a utility function, different from the equilibrium short-run utility function, if and only if the short-run utility function is such that past consumptions of any good that experience, learning, or taste changes is separable from all other goods. The class of such utility functions has been found.     

Consumption Externalities,Habit Formation and Equilibrium Efficiency*

We analyze the welfare properties of the competitive equilibrium in a capital accumulation model where individual preferences are subject to both habit formation and consumption spillovers. Using an additive specification for preferences, according to which the argument in the utility function is a linear combination of present and past values of own consumption and consumption spillovers, we analyze the circumstances under which these spillovers are a source of inefficiency. It is shown that consumption externalities have to interact with habits in order to generate an inefficient dynamic equilibrium. Finally, we characterize optimal tax policies aimed at restoring efficient decentralized paths.     

Market equilibrium with heterogeneous recursive-utility-maximizing agents

Summary This paper considers a heterogeneous agent Lucas style exchange economy. For a class of recursive utility functions containing the standard additive expected utility functions, I demonstrate that there exist market equilibria characterized by stationary (ergodic) Markov processes for consumption, portfolio holdings, asset prices and the unobserved utilities. No assumptions about market completeness are made, and there are no restrictions on the underlying information filtration.Other contributions of this paper include: (i) an existence and uniqueness theorem of intertemporal utility for the general class of recursive generators; (ii) the optimum principle as well as its corresponding Euler equation derived for the agent's consumption and portfolio choice problem under recursive utility, and (iii) a single-agent equilibrium asset pricing formula which generalizes that of Epstein and Zin (1989).This paper is a part of my PhD dissertation at the University of Toronto. I would like to thank Larry Epstein for his enthusiastic supervision, helpful discussion and valuable comments. Thanks also to Tan Wang and especially Darrell Duffie for valuable comments.     

Intergenerational preference differences and optimal national saving

This paper investigates the problem facing national planners who realize that their successors may employ different social welfare criteria for determining economic policies than they do. In such a situation, we show that the present planners may want to leave future generations a smaller capital stock than they would if they thought the stock would be managed in a way consistent with their own preferences. On the other hand, we also identify cases in which the opposite is true. We obtain the results by studying an optimal aggregate growth model the utility function of which changes randomly from one generation to the next. We analyze the model using a system of functional equations in place of the conventional Bellman equation from dynamic programming theory.     

Intellectual property rights and R&amp;D subsidies: are they complementary policies?

IPR protection and R&D subsidy are simultaneously implemented in many economies. Are they complementary policies for improving the welfare of consumers? We address this question in a dynamic general equilibrium model with innovation-driven growth. Under concave utility, the answer is yes for two cases: (1) the economy does not begin from steady state and the elasticity of intertemporal substitution (EIS) is relatively large; (2) the economy begins from steady state with either a sufficiently small initial consumption and a relatively large EIS or a sufficiently big initial consumption and a relatively small EIS. Under linear utility, the answer is yes if the discounted lifetime utility is finite in equilibrium, no matter the economy begins from the steady state or not. As empirical evidence finds cross-country heterogeneity in EIS, they are not complementary for all economies. We also identify reasonable cases whereby they are substitute policies, so we show when it is not welfare-enhancing to simultaneously implement both policies.     

Consumption and fiscal policy

This paper uses the life-cycle approach to derive an equilibrium intratemporal efficiency condition which relates the marginal utility of consumption of nondurable goods and services to the marginal utility of consumption of services from durable goods. Given this condition and the assumption that marginal utilities are affected by the level of public spending, a long-run relationship between components of private consumption and public expenditure is then postulated. The application of cointegration analysis to UK data supports the existence and uniqueness of such a long-run relationship, and estimates based on the error correction approach produce results which suggest that (i) a change in public spending has different effects on components of private consumption in the short-run, and (ii) the entire burden of long-run substitution falls on nondurable consumption.     

Relative deprivation,wealth inequality and economic growth

This paper presents an endogenous growth model where utility depends on relative deprivation as well as consumption. It is shown that a negative relationship exists between wealth inequality and equilibrium growth rate. In addition, if the concern for relative deprivation is strong enough, instantaneous utility decreases while aggregate income increases.      

Sunspot Fluctuations in Asset Prices and Business Cycles in Japan Over 1986–1999

If individuals receive utility directly from the value of their wealth, equilibrium may be indeterminate so that sunspot equilibria may exist. In such an equilibrium, the price of an asset may fluctuate stochastically, as a result of spontaneous revisions of agents' expectations. A neoclassical growth model with such a utility function is used to show that those fluctuations in asset prices can generate co-movement among output, consumption and investment, even without assuming non-convex technology. In particular, numerical results show that the model can replicate well the business cycles in Japan over the period 1986–1999.     

Dynamic effects of changes to Japanese immigration policy

This paper uses a single-sector dynamic stochastic general equilibrium model with heterogeneous households to analyse Japanese immigration policy. We examine the effects on output, consumption, factor prices, and utility. We do this for both steady states and transition paths. We find that: (a) aggregate output, investment, and consumption in Japan are likely to rise with any sort of loosening of immigration restrictions; (b) allowing more skilled immigration generates greater aggregate changes; (c) raising skilled immigration relative to unskilled immigration drives down skilled workers’ wages, consumption, and utility, while cutting the skilled to unskilled immigration share has the opposite effects; and (d) such immigration policy changes have small effects compared to those that occur naturally due to business cycle fluctuations     

RECURSIVE EQUILIBRIA IN AN AIYAGARI‐STYLE ECONOMY WITH PERMANENT INCOME SHOCKS

We prove existence of a recursive competitive equilibrium (RCE) for an Aiyagari‐style economy with permanent income shocks and derive important economic implications. We show that there exist equilibria where borrowing constraints are never binding and establish a nontrivial lower bound on the equilibrium interest rate. These results imply distinct consumption dynamics compared to existing studies. We present a new approach to solve the agent's problem that uses lattices of consumption functions to deal with permanent income shocks and an unbounded utility function. The approach provides a theoretical foundation for convergence of the time iteration algorithm widely used in applied work.     

Stochastic bequest games

In this paper, we prove the existence of a stationary Markov perfect equilibrium for a stochastic version of the bequest game. A novel feature in our approach is the fact that the transition probability need not be non-atomic and therefore, the deterministic production function is not excluded from consideration. Moreover, in addition to the common expected utility we also deal with a utility that takes into account an attitude of the generation towards risk.     

Infinite horizon CAPM equilibrium

Summary. This paper derives the equilibrium of an infinite-horizon discrete-time CAPM economy in which agents have discounted expected quadratic utility functions. We show that there is an income stream obtainable by trading on the financial markets which best approximates perfect consumption smoothing (called the {\it least variable income stream} or LVI) such that the equilibrium consumption of each agent is some multiple of the LVI and some share of aggregate output. The welfare of agents is a decreasing function of the lack of consumption smoothing achievable, measured by the distance of the LVI from the perpetuity of one unit of income for ever. If in addition the economy has a Markov structure, the LVI, and hence the equilibrium, can be calculated by dynamic programming. When the model is calibrated to US data a striking prediction emerges: the quasi-irrelevance of the bond market. Infinitely-lived agents achieve almost all their desired consumption smoothing by applying carryover strategies to equity, the proportion of agents' portfolios in bonds rarely exceeding 3%.     

家族企业接班人社会嵌入与跨代创业

当前经济社会形势下,家族企业接班人肩负着带领企业跨代创业的使命。然而,“人在江湖,身不由己”,接班人跨代创业的行为动机受到高管团队约束。基于此,根据社会嵌入理论,从认知、关系、结构三维度构建接班人嵌入到高管团队对经营多元化影响的分析模型,并对其中的作用机制进行探讨。实证研究表明,接班人和高管团队在认知嵌入上的教育背景同质性、在关系嵌入上的亲密度以及在结构嵌入上的中心化均与经营多元化呈正相关;信任在接班人和高管团队嵌入性与经营多元化关系中发挥部分中介作用。进一步分析发现,父代保守战略嵌入到高管团队中一定意义上不利于企业转型。结论表明,家族企业接班人跨代创业的行为动机受到社会嵌入的影响。     

Consumption externality, efficiency and optimal taxation in one-sector growth model

In an economy with consumption externalities, existing studies find that a competitive equilibrium is efficient in the long run and remains efficient in transitions if preferences are homothetic. This paper revisits the efficiency issue in an otherwise standard one-sector growth model where consumption externalities affect a utility via their effects on the time preference. We find that even if preferences are homothetic, the externality changes the marginal rate of substitution between now and future and leads to a disparity in the intertemporal elasticity of substitution between the centrally planned economy and a decentralized economy. As a result, a competitive equilibrium is inefficient in transition dynamics. We characterize an optimal tax/subsidy structure that enables the allocation in a decentralized economy to replicate the social optimum.