Invariance, price indices and estimation in almost ideal demand systems

Two issues are addressed in this paper. First, we explore the issue of price index invariance in the linearized Almost Ideal demand system. We establish that the Stone index, which lacks invariance, and the recently proposed invariant Laspeyres, Paasche and Tornqvist indices all generate biased and inconsistent estimators. Monte Carlo evidence shows that invariance does not necessarily lead to better estimates of price and income elasticities insofar as the Stone and Paasche indices are unambiguously inferior to the Laspeyres and Tornqvist indices, especially if prices are not strongly positively correlated. Second, we examine the merits of the widely used conditional ML estimator of the non-linear Almost Ideal system in which a prior value is chosen for the “subsistence” parameter. We find that the bias and trace mean square error increases induced by conditional estimation are modest. The choice between the linearized and the non-linear models favors the latter although in some cases linear methods are as good as non-linear. First Version Received: January 1999 / Final Version Received: March 2000     

Mending the family tree a reconciliation of the linearization and levels schools of AGE modelling

This paper offers a critical comparison between the North American levels school of applied general equilibrium modelling, and the Norwegian/Australian school of linearizers. The paper develops both the levels and linearized representations of a neoclassical multiregion trade model. This is used as a vehicle for focusing attention on similarities and differences between the two schools. The main conclusions are: (i) that both the levels and linearized versions of non-linear AGE model offer a valid starting point for obtaining accurate solutions to the non-linear equilibrium problem; (ii) when update formulae are not employed, linearized representations are particularly prone to erroneous welfare conclusions; (iii) the levels representation offers a more natural starting point for expressing accounting conditions, whereas behavioural relationships are relatively more easily expressed in a linearized representation. Recent software developments now make both approaches to the representation and solution of non-linear AGE models convenient to implement. Thus the choice of which approach to use will depend on the special needs and preferences of the economist implementing the model. The two traditions of AGE modelling have a great deal in common and both would benefit from greater cooperation.     

Revisiting the Olympic Effect

By utilizing the log‐linear gravity model, other authors have found statistically robust, permanent and large effects of hosting mega‐events (e.g. Olympics) on international exports. Surprisingly, they found that the unsuccessful bidders to host the Olympics experienced a similar impact on exports. Utilizing alternate specification such as the Poisson pseudo‐maximum likelihood (PPML) estimation that allows for heteroskedasticity prevalent in trade data, the this paper fails to find a robust positive effect of hosting and bidding for a mega‐event on total aggregate exports. Under heteroskedasticity, the parameters of log‐linearized models estimated by ordinary least squares (OLS) lead to biased estimates of the true elasticities.     

Linearized Hamiltonian of the LIBOR market model: analytical and empirical results

The linearized Hamiltonian model is proposed to extend the London Interbank Offered Rate (LIBOR) Market Model (LMM). Firstly, we studied the Hamiltonian of LMM in the framework of quantum finance, and the nontrivial upper triangle form of LIBOR drift is derived. The linearized Hamiltonian is derived to improve the explanatory capability of the model for market data. Our approach uses one more parameter to explain the initial condition and the model can be used to calibrate LIBORs with extremely high accuracy. Furthermore, the market time index is required for applying the model to multi-LIBOR, and the results imply that the LIBOR future time lattice becomes shorter as one goes from near future to distant future.     

Employment effects of the provision of specific professional skills and techniques in Germany

Based on unique administrative data, which has only recently become available, this paper estimates the employment effects of the most important type of public sector sponsored training in Germany, namely the provision of specific professional skills and techniques (SPST). Using the inflows into unemployment for the year 1993, the empirical analysis uses local linear matching based on the estimated propensity score to estimate the average treatment effect on the treated of SPST programs by elapsed duration of unemployment. The empirical results show a negative lock-in effect for the period right after the beginning of the program and significantly positive treatment effects on employment rates of about 10 percentage points and above a year after the beginning of the program. The general pattern of the estimated treatment effects is quite similar for the three time intervals of elapsed unemployment considered. The positive effects tend to persist almost completely until the end of our evaluation period. The positive effects are stronger in West Germany compared to East Germany.     

Inventory investment,investment and employment with uncertain demand

In that paper, a model of the optimal behaviour of firms with respect to the determination of capacity employment, investment and inventories is presented and estimated. Firms face an infinite horizon and an uncertain expected demand. The optimality conditions are derived, linearized and integrated. After having defined the stable optimal paths, one can proceed to the estimation of the model and to various simulations.     

The energy problem in a small open economy

The paper deals with the economic consequences of an oil price shock in a small open economy. The analysis along neoclassical lines is based upon a three-factor nested CES production function. The model takes account of capital accumulation. Analytical solutions for the short- and long-run are presented for a linearized version of the original model, which makes existing results more tractable.     

Competitive prices for a stochastic input–output model with infinite time horizon

Consider a one-sector stochastic input–output model with infinite time horizon. The technology in each time period exhibits constant returns to scale on positive linear combinations of a finite number of basic input–output pairs. Furthermore, perfect information is available as a filtration generated by finite partitions of the state space. By definition, competitive prices require expected profit maximization in every time period. The Riesz representation of a sequence of competitive price functionals yields a state-price deflator with a supermartingale property. We show that there exists a competitive price system for some feasible program if and only if there is No Free Production (NFP). Furthermore, there exists a competitive price system for a particular program if and only if if NFP holds and the program is short-run efficient. This model includes a securities market model with or without convex cone trading constraints as a special case. Under these circumstances, NFP reduces to No Arbitrage and we recover a version of the fundamental theorem of asset pricing. The author expresses gratitude for the advice of two anonymous referees, one who pointed out the simple way to prove the key lemma and the other who helped integrate the conclusions into the existent literature.     

User Charges as Redistributive Devices

In this model, a mix of public and private provision of private goods arises naturally in the economy. We characterize the social optimum in the presence of a linear tax/public expenditure system and show how a user charge can be welfare- or Pareto-improving, when the users are the poor. The charge discourages the rich from opting into the public program and allows the policymaker to restructure the tax/expenditure system in a way that is beneficial for the poor. If the ensuing welfare gain is large enough to outweigh the loss for the remaining users, a charge is desirable.     

A Note on Attitude as a Factor in Learning Economics

Although one might naturally assume that students interested in economics will learn more in an introductory course than those not interested in the subject, this assumption had to be tested. Using a specially designed “Questionnaire on Student Attitude Toward Economics” on a pretest and posttest basis, and accounting for previous course work, the student's verbal and quantitative skills, and student program requirements, Karstensson and Vedder employed linear multiple regression analysis and found a positive relationship between precourse attitude and course grade. Changes in student attitude which occurred during the course were also analyzed.     

A locally linear estimation of regression discontinuity

In this paper, we propose a locally linear estimation of a regression discontinuity model. The proposed estimator is applicable to evaluation of the effectiveness of the program treatment, and it improves upon the existing literature by providing not just the treatment effect at discontinuity but also insight of the treatment effect on those near discontinuity. Under some familiar conditions, we establish the consistency and asymptotic normality of the proposed estimator. We also provide an easy to compute consistent covariance matrix.     

Infinite-horizon competitive programs are optimal

For infinite-horizon optimal-growth problems the standard result in the literature says that a program is optimal if and only if associated with it is a sequence of present-value prices at which the program satisfies (i) a set of myopic competitive conditions, and (ii) an asymptotic transversality condition. The principal result of this paper points out the interesting and surprising fact that at least for a class of multisector models where the production side is described by a simple linear model, and there are some limiting primary factors, the competitive conditions alone characterize an optimal program.     

OPTIMAL MONETARY POLICY AND ASSET PRICE MISALIGNMENTS

This paper analyses the relationship between monetary policy and asset prices in the context of optimal policy rules. The transmission mechanism is represented by a linearized rational expectations model augmented for the effect of asset prices on aggregate demand. Stabilization objectives are represented by a discounted quadratic loss function penalizing inflation and output gap volatility. Asset prices are allowed to deviate from their intrinsic value due to momentum trading. We find that in the presence of wealth effects and inefficient markets, asset price misalignments from their fundamentals should be included in the optimal interest rate reaction function.     

Accomplice Witnesses and Organized Crime: Theory and Evidence from Italy

We develop an agency model of organized crime accounting for the main trade‐offs involved in the introduction of an accomplice‐witness program. We characterize the optimal policy and identify its main determinants in a framework where public officials can be dishonest. Our predictions are tested by using data for Italy before and after the introduction of the 1991 accomplice‐witness program. As predicted by the model and the earlier antitrust literature, the program appears to have strengthened deterrence and enhanced prosecution. Moreover, consistent with a novel prediction of our theory, the evidence suggests that the program efficacy is affected by the judicial system efficiency.     

An optimal auction for capacity constrained bidders: a network perspective

This paper examines the problem of a seller with limited supply selling to a group of agents whose private information is two-dimensional. Each agent has a constant marginal value for the good up to some capacity, thereafter it is zero. Both the marginal value and the capacity are private information. We describe the revenue maximizing Bayesian incentive compatible auction for this environment. A novel feature of the analysis is an interpretation of an optimal auction design problem in terms of a linear program that is an instance of a parametric shortest path problem on a lattice. We thank the referees for a number of useful suggestions that have been incorporated into the paper. Mallesh Pai suggested the argument given in Lemma 1. The research was supported in part by the NSF grant ITR IIS-0121678.     

以企业为实施主体的美国NII计划组织实施方法及其对我国重大专项组织实施的启示

美国NII计划类似于我国的重大专项,它切合经济社会发展的需求,承担培育重大战略产业、创造新经济增长点的使命。在美国NII计划的组织实施中,美国政府组建了推动"技术—产业—经济"战略布局的领导组织(IITF),制定了确保企业参与的五项原则以及为之服务的政府工作细则和目标,为企业建设NII创造了公平的市场法律环境、政策激励环境以及有效市场需求。 ?     

A Pollution Offset System for Trading Non-Point Source Water Pollution Permits

Water pollution from non-point sources is a global environmental concern. Economists propose tradable permit systems as a solution, but they are difficult to implement due to the nature of non-point sources. We present a pollution offset system for trading non-point source water pollution permits. Conventional pollution offset systems suffer from thin markets and transaction costs. In this paper, we show how to overcome these problems with a centrally managed common-pool market. We define permits as allowable nitrate loading to a groundwater aquifer. This trading system utilizes estimates of potential nitrate leaching from land uses, a set of transport coefficients generated from a simulation of nitrate transport in groundwater, an online trading system, and a linear program to clear the market. We illustrate the concept using a hypothetical case study.     

On ascending Vickrey auctions for heterogeneous objects

We construct an ascending auction for heterogeneous objects by applying a primal-dual algorithm to a linear program that represents the efficient-allocation problem for this setting. The auction assigns personalized prices to bundles, and asks bidders to report their preferred bundles in each round. A bidder's prices are increased when he belongs to a “minimally undersupplied” set of bidders. This concept generalizes the notion of “overdemanded” sets of objects introduced by Demange, Gale, and Sotomayor for the one-to-one assignment problem. Under a submodularity condition, the auction implements the Vickrey-Clarke-Groves outcome; we show that this type of condition is somewhat necessary to do so. When classifying the ascending-auction literature in terms of their underlying algorithms, our auction fills a gap in that literature. We relate our results to various ascending auctions in the literature.     

On methods of optimal portfolio construction

The transition from a centrally planned economy to a market economy in Poland has caused dynamic changes in the number and structure of potential investors of the stock exchange market. This phenomenon, unknown in the past, needs a new approach to statistical methods of stock market analysis. The paper presents two methods of optimal portfolio construction. The first one leads to the square programming problem. Applying the Lagrange multipliers, we obtain a system of algebraic equations which can be solved by the special algorithm proposed in the paper. The second method reduces the mentioned above square program to the linear programming problem which can be solved using the simplex method.