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.     

Optimal Intertemporal Consumption and Involuntary Memories of Consumption

Recent studies introduce the notion of treating autobiographical memories of past pleasurable experiences as assets and expanding the discounted utility model to include the utility of memories of past consumption. Recent studies in psychology have found that involuntary autobiographical memories are common in everyday life. This paper builds on these two strands in the literature by expanding the discounted utility model to include the utility of involuntary memories of past consumption. Optimal control theory is used to develop a continuous‐time optimal consumption model that takes into account the fact that consumption may generate involuntary memories that arrive at random times. The model is used in an in‐depth analysis of optimal consumption with memories. It is shown that memories shift consumption to earlier times. This effect gets weaker as the time horizon gets longer, and it vanishes entirely when the time horizon is infinite.     

HETEROGENEOUS RISK ATTITUDES IN A CONTINUOUS‐TIME MODEL*

We prove that every continuous‐time model in which all consumers have time‐homogeneous and time‐additive utility functions and share a common probabilistic belief and a common discount rate can be reduced to a static model. This result allows us to extend some of the existing results of the representative consumer and risk‐sharing rules in static models to continuous‐time models. We show that the equilibrium interest rate is lower and more volatile than in the standard representative consumer economy, and that the individual consumption growth rates are more dispersed than in the absence of uncertainty.     

HUMAN CAPITAL DISTRIBUTION,GROWTH AND TRADE

Distribution differences in human capital matter for a country's growth and trade. While the existing literature considers only the diversity difference in talent distribution, we argue that the kurtosis difference is also an important factor. In a two‐sector equilibrium growth model, where the production function is supermodular for the consumption‐good sector and submodular for the R&D sector, we prove that the diversity effect and kurtosis effect are opposite to each other. A country endowed with more diverse but leptokurtic talent distribution may have lower growth rate and import submodular goods, opposite to the conventional result from considering only the diversity difference.     

Trend-reverting fluctuations in the life-cycle model

Aggregate time series provide evidence of short-term dynamic adjustment that appears to be governed by complex or negative real eigenvalues. This finding is at odds with the predictions of reasonably parameterized, convex one-sector growth models with complete markets. We study life-cycle economies in which aggregate saving depends non-trivially on the distribution of wealth among cohorts. If consumption goods are weak gross substitutes near the steady-state price vector, we prove that the unique equilibrium of a life-cycle exchange economy converges to the unique non-monetary steady state via damped oscillations. We also discuss examples and extensions.     

FIXED COSTS,THE BALANCED BUDGET MULTIPLIER AND WELFARE*

In a two‐sector model, where one of the sectors is monopolistically competitive and subject to increasing returns to scale but without love for variety, we analyse the effects of a balanced budget fiscal expansion. Such an expansion could increase the welfare of the representative individual, if elasticities of substitution in production and consumption are low. A reorganization of production takes place—increasing returns enabling a rise in real income.     

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.     

MILITARY SPENDING,THREATS AND STOCHASTIC GROWTH

This paper analyses the impact of home military spending and foreign military threat on economic growth in a stochastic endogenous growth model involving the supply‐side and demand‐side effects produced by military spending. The paper states that an increase in home military spending affects economic growth through three channels, including the crowding‐out effect, the spin‐off effect, and the resource mobilization effect. The net effect which depends on these three channels is ambiguous. Hence, we demonstrate that there exists an optimal defence burden that maximizes the economic growth rate. Furthermore, the optimal defence burden depends on the degree of risk preference. Namely, the optimal defence burden of the risk‐loving agent is more than that of the risk‐neutral agent, and in turn is more than that of the risk‐averse agent. At the same time, we prove that the relationship between the volatility in military spending and economic growth also depends on the degree of risk preference. In addition, we show that greater volatility in foreign military spending leads to a decrease in home aggregate consumption, and hence speeds up economic growth in the home country.     

INSURANCE‐INDUCED MORAL HAZARD: A DYNAMIC MODEL OF WITHIN‐YEAR MEDICAL CARE DECISION MAKING UNDER UNCERTAINTY

This study quantifies the moral hazard effect of health insurance on medical expenditure by estimating a dynamic model of within‐year medical care consumption that allows for insurance selection, endogenous health transitions, and individual uncertainty about medical care prices in an environment where insurance has nonlinear cost‐sharing features. The results suggest that moral hazard accounts for 53.1%, on average, of total annual medical expenditure when insured. This estimate is significantly different, and generally larger, than that produced by an alternative model that is representative of the annual medical care decision‐making models commonly found in the literature.     

Fiscal Spending,Relative‐Price Dynamics,and Welfare in a World Economy*

This paper analyzes the dynamics of a 2 × 2 × 2 Heckscher–Ohlin model where foreign asset holdings and capital accumulation are independently determined by optimizing agents. Each country has two production sectors, both of whose products are used for consumption, and an investment sector, which uses one of the two commodities to accumulate real capital. In this setting we examine the effects of fiscal spending on the equilibrium paths of interest rates and prices and each country's lifetime utility. The welfare effect is found to consist of the static terms‐of‐trade effect, the dynamic foreign asset effect and the direct income‐loss effect.     

Piecemeal Reform of Domestic Indirect Taxes toward Uniformity in the Presence of Pollution: with and without a Revenue Constraint

The literature on indirect tax reforms in pollution‐ridden economies is quite limited. This paper, using a general equilibrium model of a perfectly competitive small open economy with both production‐ and consumption‐generated pollution, considers the welfare implications of tax reforms that take the structure of consumption and production taxes toward uniformity. Specifically, both in the presence and absence of a binding government revenue constraint, we derive sufficient conditions for welfare improvement in the case where we implement (i) reforms in either production or consumption taxes, and (ii) reforms in both consumption and production taxes.     

ENDOGENOUS CYCLES IN A SIMPLE MODEL WITH LAGGED EXTERNALITIES ON PRODUCTIVITY

This paper presents a simple model of endogenous cycles. In the model, working experience creates learning‐by‐doing externalities that improve labor productivity but it takes long time before the externalities come into effect. In addition, individuals have preferences with a subsistence consumption level. In the presence of the subsistence consumption requirement, a productivity increase generates the income effect that surpasses the substitution effect, and individuals choose to increase leisure time at the expense of supplying labor. The interactions between productivity changes through the lagged externalities and labor supply generate cycles endogenously. The model analysis shows that the dynamics exhibit cyclical fluctuations around a unique steady state.     

International Economic Interdependence and Exchange‐rate Adjustment under Persistent Stagnation

Using a two‐country, two‐commodity dynamic optimization model with general homothetic preference for the commodities, this paper examines the effects of a tariff and a quota on consumption and employment in the case where persistent unemployment arises due to a liquidity trap. A trade restriction improves the current account, which causes the home currency to appreciate and harms the competitiveness of home firms. Therefore, home employment and consumption decrease while foreign employment and consumption increase. Tariff‐quota equivalence is found to be valid. Preference, technological and policy parameter changes that improve the current account in general worsen home unemployment.     

Consumption adaptation,anticipation‐bias,and optimal income taxation

Adaptation is omnipresent but people systematically fail to correctly anticipate the degree to which they adapt, leading them to make irrational intertemporal decisions. This paper concerns optimal income taxation to correct for such anticipation‐biases in a framework where consumers adapt to earlier consumption levels. The analysis is based on a general equilibrium OLG model with endogenous labor supply and savings where each consumer lives for three periods. The results show how a paternalistic government may correct for the effects of anticipation‐bias through a combination of time‐variant marginal labor income taxes and savings subsidies/taxes. The optimal policy mix remains the same, irrespective of whether consumers commit to their original life time plan for work hours and consumption or reoptimize later on when realizing that they have already adapted more than expected.     

Optimal age‐dependent income taxation in a dynamic extensive model: The case for negative participation tax on young people

We consider optimal age‐dependent income taxation in a dynamic model where the labor‐leisure choice is the extensive margin, each household faces idiosyncratic shocks to labor productivity and a pecuniary cost to work, and there is no insurance market against the shocks. We show that the well‐known property of the optimal participation tax rate in the static model continues to hold in our dynamic economy, that is, the participation tax rates for some income groups with low consumption are likely negative. In dynamic models, the optimal participation tax rate depends on age and on labor income. Our numerical simulations suggest that a negative participation tax should be restricted to young households.     

差别电价传导机制及延迟性的系统动力学模拟

本文以高耗能企业中的电解铝企业为例,运用差别电价政策的系统动力学仿真模型,模拟差别电价对企业的单位产品成本、用电量等指标的影响以及其最终引起企业经营决策的变化。研究表明:差别电价对电解铝企业的"用电量增加"、"生产量"具有明显的降低效果,且随着时间的推移,此影响的效果越来越显现,并且差别电价对高耗能企业的生产决策影响具有延迟效应。     

Time Preference and Income Convergence in a Dynamic Heckscher–Ohlin Model

This paper shows that income convergence in an open‐economy setting hinges upon how the time discount rate of the households is determined. As opposed to the case of constant time discount rate where cross‐country income divergence may emerge, the small open economy may catch up with the rest of the world if the time discount rate increases with consumption. In contrast, if the time discount rate decreases with consumption, then the small open economy fails to catch up with the rest of the world under free trade of commodities.     

Buying a Home with a Resale Value: Location,Location, Location*

We develop a dynamic multiregion model, where a household's choice of housing location depends on its current wealth and its current type, and involves both consumption and investment considerations. The relative strength of the consumption motive and the investment motive determines the equilibrium pattern of residential sorting. A strong investment (consumption) motive implies sorting according to household type (wealth). The model predicts that large house‐price fluctuations are associated with a low degree of sorting by type. This prediction is consistent with evidence from US metropolitan areas when income, education, and age are used as proxies for household type.     

搜索、政府花费和失业

本文在将搜索理论和经典的经济增长理论结合的基础上引入生产性政府花费,讨论了政府花费对就业和消费的影响。利用最一般的生产和效用函数,证明了均衡状态存在的唯一性。当失业工人和空闲职位的匹配是有效时,表示经济系统的四维动力系统存在一个稳定的二维流形。     

INTERTEMPORAL UTILITY SMOOTHING: THEORY AND APPLICATIONS

This paper reviews models of intertemporal choice designed to be consistent with a phenomenon called a preference for spread; that is, where a decision‐maker prefers to spread good and bad consumption evenly over time. We closely examine the notion of utility smoothing adopted in these models as a source of the preference for spread. The paper also reviews extensions of these models where a strong aversion to volatility involved in a utility sequence causes preferences to be nonmonotone. Furthermore, to gain a better understanding of the behaviour implied by these models, we apply them to the Diamond growth model.