R&D与生产率——基于中国制造业的实证研究

本文运用中国四位数制造产业数据对R&D与生产率之间的关系进行了实证检验。通过估计两种不同的生产函数模型,本文发现R&D对生产率有显著正影响。在控制了市场因素和产权因素的影响后,R&D与生产率之间仍旧表现出显著的正相关关系。本文还发现,R&D对生产率的促进作用也依赖于产业技术机会,高科技产业的R&D产出弹性显著大于非高科技产业的R&D产出弹性。     

TRAINING,TURNOVER, AND SEARCH*

This article explores a model of firm‐specific training in a job search environment with labor turnover. The main substantive finding is a positive association between training and wages (when dispersed). The article then precisely characterizes how both wage dispersion and firm profitability depend on the flow value b≥ 0 of workers' unmatched time. It is shown that: (i) for all high values b, no equilibrium exists; (ii) for intermediate values b, multiple equilibria arise, where firms earn zero profits, and choose from a general wage distribution; (iii) for all lower values b, there is a unique equilibrium, with firms earning positive profits, and choosing from an atomless set of wages.     

Strategy-proof risk sharing

We consider risk sharing problems with a single good and a finite number of states. Agents have a common prior and their preferences are represented in the expected utility form and are risk averse. We study efficient and individually rational risk sharing rules satisfying strategy-proofness, the requirement that no one can ever benefit by misrepresenting his preference. When aggregate certainty holds, we show that “fixed price selections” from Walrasian correspondence are the only rules satisfying efficiency, individual rationality, and strategy-proofness. However, when aggregate uncertainty holds, we show that there exists no rule satisfying the three requirements. Moreover, in the two agents case, we show that dictatorial rules are the only efficient and strategy-proof rules. Dropping the common prior assumption in the model, we show that this assumption is necessary and sufficient for the existence of rules satisfying the three main requirements in the two agents and aggregate certainty case.     

On the Non-Existence of Redundant Options

In a seminal paper, Ross (Q J Econ 90:75–89, 1976) shows that if security markets are resolving, then there exist (non-redundant) options that generate complete security markets. Complementing his work, Aliprantis and Tourky (2002) show that if security markets are strongly resolving and the number of primitive securities is less than half the number of states, then every option is non-redundant. Our paper extends Aliprantis and Tourky’s result to the case when their condition on the number of primitive securities is not imposed. Specifically, we show that if there exists no binary payoff vector in the asset span, then for each portfolio there exists a set of exercise prices of full measure such that any option on the portfolio with an exercise price in this set is non-redundant. Since the condition that there exists no binary payoff vector in the asset span holds generically, redundant options are thus rare. I am grateful to an anonymous referee for very helpful comments. Research support from the School of Business at The George Washington University is gratefully acknowledged     

Monetary equilibrium in an overlapping generations model with productive capital

Summary We study perfect foresight competitive equilibrium in an overlapping generations model with productive capital and a fixed nominal stock of money. We obtain almost-complete characterizations of (a) the existence of a monetary equilibrium from an arbitrary initial capital stock, and (b) the existence of anefficient monetary equilibrium from an arbitrary initial capital stock. When the initial capital stock is no larger than the golden rule stock, the necessary and sufficient condition for both (a) and (b) is the dynamic inefficiency (in the sense of Malinvaud) of the autarkic (or nonmonetary) equilibrium from the same initial stock. However, this condition, though necessary, isnot sufficient for the existence of a monetary equilibrium when the initial stock exceeds the golden rule stock (and still more conditions are needed for anefficient monetary equilibrium to exist). We provide characterizations for these cases, and as corollaries obtain examples in which (a) the nonmonetary equilibrium is inefficient but no monetary equilibrium exists, and (b) monetary equilibria exist but no efficient monetary equilibrium does.We are grateful to a co-editor and an anonymous referee for comments that greatly improved the exposition in the paper.     

Private money and bank runs

Abstract This paper studies bank runs in a model with private money. We show that allowing claims on demand deposits to circulate as a medium of exchange can help prevent bank runs. In our model, there exists a unique banking equilibrium where no one demands early withdrawals of real goods and agents in need of liquidity use private money to finance consumption. With private money, the unique equilibrium not only eliminates bank runs but also improves banking efficiency. The implications of our model are consistent with the evidence from the banking history of the United States.     

Stable International Environmental Agreements: An Analytical Approach

In this paper we examine the formation of international environmental agreements (IEAs). We show that the welfare of the signatories does not increase monotonically with respect to the number of signatories. We provide an analytical solution of the leadership model. In particular, we find that if the number of countries is greater than four then there exists a unique stable IEA with either two, three, or four signatories. Furthermore, we show that the welfare of the signatories is almost at its lowest level when the IEA is stable. While in our model each country's choice variable is emissions, we extend our results to the case where the choice variable is abatement efforts.     

A NONCOOPERATIVE SHIPPING COURNOT DUOPOLY WITH LINEAR‐QUADRATIC TRANSPORT COSTS AND CIRCULAR SPACE*

The mixed strategy equilibria in a location quantity duopoly model with circular markets are investigated. We find that a continuum of equilibria exists when the transport cost function is linear. However, if costs are strictly concave or convex, most strategies fail to qualify as equilibria. For any integer n, there are nondegenerate mixed strategy equilibria in which each firm locates at n possible locations with equal probability. This result explains possible outcomes in which firms’ on‐path locations are not minimally or maximally differentiated.     

Private provision of a discrete public good: efficient equilibria in the private-information contribution game

We study the voluntary provision of a discrete public good via the contribution game. Players independently and simultaneously make nonrefundable contributions to fund a discrete public good, which is provided if and only if contributions cover the cost of production. We characterize nonconstant continuous symmetric equilibria, giving sufficient conditions for their existence. We show the common normalization by which players’ values are distributed over [0, 1] is not without loss of generality: if the distribution over this interval has continuous density f with f(0) >  0, then no (nonconstant) continuous symmetric equilibrium exists. We study in detail the case in which players’ private values are uniformly distributed, showing that, generically, when one continuous equilibrium exists, a continuum of continuous equilibria exists. For any given cost of the good, multiple continuous equilibria cannot be Pareto ranked. Nevertheless, not all continuous equilibria are interim incentive efficient. The set of interim incentive efficient equilibria is exactly determined. The authors thank Manfred Dix, George Mailath, Andrew Postlewaite, and an anonymous referee for their comments.     

Superstition and real estate prices: transaction-level evidence from the US housing market

We investigate the impact of superstition on prices paid by Chinese-American home buyers. Chinese consider 8 lucky and 4 unlucky. Lacking explicit buyer ethnicity identifiers, we develop a binomial name classifier, a machine learning approach applicable to any data set containing names, that allows for falsification tests using other ethnic groups, and mitigates ambiguity from the transliteration of Chinese characters into the Latin alphabet. Chinese buyers pay 1–2% premiums for addresses including an 8 and 1% discounts for addresses including a 4. These results are unrelated to unobserved property quality; no premium exists when Chinese sell to non-Chinese. The persistence of superstitions reflects the extent of cultural assimilation.     

Semicollusion vs. Full Collusion: The Role of Demand Uncertainty and Product Substitutability

We examine the profitability of two different cartel organizational forms: full collusion, under which firms collude on both price and quality, and semicollusion, under which firms collude on price only. We show that, in the presence of demand uncertainty that cannot be contracted upon in the cartel agreement, firms may be better off limiting their collusive agreement to price only. However, a positive relationship between demand uncertainty and the relative profitability of semicollusion exists only for low levels of demand substitutability. The converse is true for high levels of demand substitutability. Therefore, if demand substitutability is sufficiently high, no level of demand uncertainty will make semicollusion the optimal organizational form. In contrast, semicollusion is guaranteed to be optimal for a sufficiently low level of demand substitutability. The market structure described is motivated by and closely parallels that of shipping cartels. Received September 29, 2000; revised version received December 10, 2001 Published online: November 11, 2002     

Exogeneity, causality, and co-breaking in economic policy analysis of a small econometric model of money in the UK

Since the objective of economic policy is to change target variables in the DGP, when economic policy analysis uses an econometric model, it is important that the model delivers reliable inferences about policy responses in the DGP. This requires that the model be congruent and encompassing, and hence exogeneity, causality, cointegration, co-breaking, and invariance all play major roles. We discuss these roles in linear cointegrated VARs, prior to illustrating their importance in a bivariate model of money and interest rates in the UK over the last century.Financial support from the UK Economic and Social Research Council under grant L116251015, and the EUI Research Council grantEconometric Modelling of Economic Time Series, is gratefully acknowledged. Early research for the paper was done whilst Mizon was Visiting Fellow in the Economics Program of the RSSS at ANU, where he benefited from the excellent research environment and discussions with Adrian Pagan. We are grateful to Hans-Martin Krolzig for helpful discussions on the topic. We also thank members of the Research Department, Norges Bank, Oslo, the particpants at theWorkshop on Money Demand in Europe, Humboldt University, October 1997, two referees, and the editors Helmut Lütkepohl and Jürgen Wolters for their valuable comments. The data may be obtained from the internet, http://wotan.wiwi.huberlin.de/oekonometric./engl/data.html     

Noncooperative Equilibrium and Chamberlinian Monopolistic Competition

This paper addresses the existence of equilibrium for a nonatomic Bertrand game in a Chamberlinian environment. We reformulate O. Hart′s model (Rev. Econ. Stud. 52, 1985, 529–546) as a nonatomic game and show that under dispersion of tastes and continuity of the tastes density, there exists a pure-strategies ε-equilibrium where prices exceed marginal cost. Unlike Hart′s model there is no need to impose uniformity (or even independence) on the distribution of the m-tuple of differential commodities that consumers care about. Moreover, demand curves are allowed to vary across firms and in equilibrium firms may earn profits. Journal of Economic Literature Classification Numbers: B21, D43, L13.     

从"易变"到"应变":科技型员工生涯适应力促进机制

生涯适应力是员工应对多样化工作环境所需的一种心理资源。如何通过管理手段提升科技型员工生涯适应力仍有待研究。基于生涯建构理论,通过构建跨层次有调节的中介模型,检验科技型员工生涯适应力的促进机制和边界条件。来自78个科技型企业团队、274名领导成员的两阶段配对数据显示：工作多样性正向促进科技型员工生涯适应力,而员工主动行为在二者关系中起部分中介作用,并且变革型领导调节该中介作用。在高变革型领导下,工作多样性通过科技型员工主动行为显著影响生涯适应力的中介效应,而在低变革型领导下,该中介效应不显著。研究启示科技型组织可以通过调整变革型领导管理方式和设计多样性工作等举措提升科技型员工生涯适应力。     

Public decisions: Solidarity and the status quo

A public decision model specifies a set of alternatives, a variable population, and a common set of admissible preferences. We study the implications of the principle of solidarity, for social choice functions in all such models. The principle says that when the environment changes, all agents not responsible for the change should either all weakly win, or all weakly lose. Under weak additional requirements, but regardless the domain of preferences, each of two formulations of this principle, population-monotonicity and replacement-domination, imply coalition-strategy-proofness; that the choice only depends on the set of preferences that are present in the society, but not on the number, nor on the labels of agents having particular preferences; and that there exists an alternative always weakly Pareto-dominated by the alternative selected by the rule. Replacement-domination is generally at least as strong as population-monotonicity.     

经济转轨中国有资本比重的最优路径选择——一个动态模型

This paper presents a dynamic model based on the utility maximum decisions of both the government and private sectors to study the optimal withdrawing path of state-owned capital in economic transition. Numerical simulation shows that: (1) an optimal transition path still exists when treating government and private sectors separately, (2) when the transition cost is higher than its critical value, the economy will never start a transition by itself. In addition, this analysis offers theoretical supports for some reform policies adopted by governments during transition. __________ Translated from Jingjixue Jikan 经济学(季刊) (China Economic(Quarterly)), 2007, 6(2): 561–580     

COHERENCY AND COMPLETENESS OF STRUCTURAL MODELS CONTAINING A DUMMY ENDOGENOUS VARIABLE*

Let y be a vector of endogenous variables and let w be a vector of covariates, parameters, and errors or unobservables that together are assumed to determine y. A structural model y=H(y, w) is complete and coherent if it has a well‐defined reduced form, meaning that for any value of w there exists a unique value for y. Coherence and completeness simplifies identification and is required for many estimators and many model applications. Incoherency or incompleteness can arise in models with multiple decision makers, such as games, or when the decision making of individuals is either incorrectly or incompletely specified. This article provides necessary and sufficient conditions for the coherence and completeness of simultaneous equation systems where one equation is a binomial response. Examples are dummy endogenous regressor models, regime switching regressions, treatment response models, sample selection models, endogenous choice systems, and determining if a pair of binary choices are substitutes or complements.     

Characterization of a class of moral-hazard, adverse selection games

Studying a principal-agent game in which the agent alone observes the state of the world and reports it, but the moral hazard is not reducible, shows that, if the principal uses all signals, then no solution exists, i.e. there is no contract that elicits truth-telling and motivates the agent to exert effort. When the principal does not use signals on the state of the world that seem irrelevant, a solution exists in which some of the ex post signals on outcome are not used, even though they obey the informativeness condition of Holmstrom (Bell Journal of Economics, 1979, 10, 74–91).     

How efficient is maize production among smallholder farmers in Zimbabwe? A comparison of semiparametric and parametric frontier efficiency analyses

The controversial Fast Track Land Reform Programme in Zimbabwe that redistributes commercially-owned farmland to smallholder households has caused concerns about the efficiency of agricultural production in the country. In this paper, we estimate the efficiency of resource use among smallholder farmers in Zimbabwe when producing maize, the staple crop in the country. Using both a semiparametric model and a fully parametric stochastic frontier model, we find significant production shortfalls for smallholder maize production. While labor, capital, and land all significantly affect the total output, the estimated mean efficiency score for farms with less than 10 hectares of land (A1) appears to be under 0.75, and for the entire sample (A1 and A2) it ranges between 0.595 and 0.772. There clearly exists a great potential for maize farmers to improve the technical efficiency and increase the total output. Gender and age of the household head, access to extension services, and activities of other crops significantly affect the technical efficiency of smallholder maize production in Zimbabwe. We also find that all farms operate under increasing returns to scale and that the technical efficiency score tends to increase with the level of output.     

The importance of considering optimal government policy when social norms matter for the private provision of public goods

We study optimal government policy in a reference model (Rege, 2004, Journal of Public Economic Theory, 6, 65–77) of public good provision and social approval in a dynamic setting. We show that even if complete adherence to the social norm maximizes social welfare it is by no means necessarily optimal to push society toward it. We stress the different roles of social externality and the public good problem. We discuss the problem with the standard crowding in and out argument and analyze the relationship with Pigouvian taxes. We discuss the role of the cost of public funds and show how it can create path dependency, the multiplicity of both optimal equilibria and optimal paths, and discuss the role of parameter instability.