Consistent estimation in the bilinear multivariate errors-in-variables model

A bilinear multivariate errors-in-variables model is considered. It corresponds to an overdetermined set of linear equations AXB=C, A∈ℝ^m×n, B∈ℝ^p×q, in which the data A, B, C are perturbed by errors. The total least squares estimator is inconsistent in this case.  An adjusted least squares estimator is constructed, which converges to the true value X, as m →∞, q →∞. A small sample modification of the estimator is presented, which is more stable for small m and q and is asymptotically equivalent to the adjusted least squares estimator. The theoretical results are confirmed by a simulation study. Acknowledgements. We thank two anonymous reviewers for their suggestions and corrections.? A. Kukush is supported by a postdoctoral research fellowship of the Belgian office for Scientific, Technical and Cultural Affairs, promoting Scientific and Technical Collaboration with Central and Eastern Europe.? S. Van Huffel is a full professor with the Katholieke Universiteit Leuven.? I. Markovsky is a research assistant with the Katholieke Universiteit Leuven.? This paper presents research results of the Belgian Programme on Interuniversity Poles of Attraction (IUAP V-22), initiated by the Belgian State, Prime Minister's Office – Federal Office for Scientific, Technical and Cultural Affairs of the Concerted Research Action (GOA) projects of the Flemish Government MEFISTO-666 (Mathematical Engineering for Information and Communication Systems Technology), of the IDO/99/03 project (K.U. Leuven) “Predictive computer models for medical classification problems using patient data and expert knowledge”, of the FWO projects G.0078.01, G.0200.00, and G0.0270.02.? The scientific responsibility is assumed by its authors.     

国际资本流动的新特点与我国利用外资的基本思路

中国正式加入WTO，标志着中国对外开放进入了一个新的阶段，本文试图在分析国际资本流动的新特点的基础上，从完善市场经济制度和投资环境，引资方式创新，发挥利用外资对结构调整战略的配合作用，以及利用外资与宏观经济目标的相互协调等方面，提出中国利用外资的基本思路。     

Forecasting residential burglary

Following the work of Dhiri et al. [Modelling and predicting property crime trends. Home Office Research Study 198 (1999). London: HMSO] at the Home Office predicting recorded burglary and theft for England and Wales to the year 2001, econometric and time series models were constructed for predicting recorded residential burglary to the same date. A comparison between the Home Office econometric predictions and the less alarming econometric predictions made in this paper identified the differences as stemming from the particular set of variables used in the models. However, the Home Office and one of our econometric models adopted an error correction form which appeared to be the main reason why these models predicted increases in burglary. To identify the role of error correction in these models, time series models were built for the purpose of comparison, all of which predicted substantially lower numbers of residential burglaries. The years 1998–2001 appeared to offer an opportunity to test the utility of error correction models in the analysis of criminal behaviour. Subsequent to the forecasting exercise carried out in 1999, recorded outcomes have materialised, which point to the superiority of time series models compared to error correction models for the short-run forecasting of property crime. This result calls into question the concept of a long-run equilibrium relationship for crime.     

An investigation of transformation-based prediction interval for the Weibull median life

Statistical inference based on the Weibull distribution, a distribution widely used in reliability and survival analysis, is usually difficult as it often involves numerical computation and approximation. However, this distribution can be transformed to near-normality by a simple power transformation. Based on this transformation, a prediction interval (PI) for its median can be easily constructed through an inverse transformation. The procedure for selecting the best power transformation through minimizing Kullback-Leibler information is described. The property of this transformation-based PI is investigated. Simple correction factors are also proposed. It is shown that the transformation-based PI with corrections performs well, irrespective of the sample size and parameter values. Simulation results show that the new PI generally outperforms the existing PI. Numerical examples are given for illustration.     

Optimality conditions¶and bubbles in sequential economies¶and bounded relative risk-aversion

We provide specific qualifications in order that Kuhn–Tucker type Euler equations and transversality conditions at infinity hold in stochastic equilibrium models with heterogeneous agents and where assets are traded in sequential markets. It is not assumed that uncertainty is modeled as an event-tree structure or that preferences are necessarily bounded. We also describe an important class of preferences based on bounded relative risk aversion which yields relevant simplifications. Our results are used to establish conditions that rule out asset pricing bubbles. Specific examples of economies with bubbles are also discussed. Received: 28 January 2002 / Accepted: 19 July 2002 We are grateful to the editor and an anonymous referee for their valuable comments. This research was partially supported by MURST (Italy), National Group on “Nonlinear Dynamics and Stochastic Models in Economics and Finance”.     

Endogenous Growth and Negative Externalities

Received March 5, 2001; revised version received August 5, 2002 Published online: April 30, 2003     

Bayesian MCMC Mapping of Quantitative Trait Loci in a Half-sib Design: a Graphical Model Perspective

Graphical models provide a powerful and flexible approach to the analysis of complex problems in genetics. While task-specific software may be extremely efficient for any particular analysis, it is often difficult to adapt to new computational challenges. By viewing these genetic applications in a more general framework, many problems can be handled by essentially the same software. This is advantageous in an area where fast methodological development is essential. Once a method has been fully developed and tested, problem-specific software may then be required. The aim of this paper is to illustrate the potential use of a graphical model approach to genetic analyses by taking a very simple and well-understood problem by way of example.     

Inequality foundations of concentration measures: An application to the Hannah-Kay indices

The aim of this paper is to provide a connection between concentration and inequality. In particular, we show that the general entropy inequality indices are, among inequality measures, those consistent with the whole set of Hannah-Kay concentration indices. We isolate the inequality component underlying concentration measures, obtaining an explicit additive decomposition of the change in concentration into the change in its two components, i.e., inequality and the number of firms. This relationship proves to be valid for the whole set of Hannah-Kay concentration indices, and embodies as particular cases some others previously found in the literature. We are particularly grateful to Emilio Cerdá for helpful comments on the mathematical formulation of the paper. The second author also acknowledges support through the European Commission Project #ERBCHRXCT980248.     

Does a Switch of Budget Regimes Affect Investment and Managerial Discretion of State-Owned Enterprises? Evidence from Italian Firms

We investigate the investment decisions of Italian state-owned enterprises (SOEs) across budget constraint regimes and carry out a natural experiment that exploits a regime switch in 1987. Drawing on the theory of capital market imperfections, we apply an empirical framework for investment analysis to a panel of manufacturing SOEs in competitive industries. We identify parallels between SOEs and widely held, quoted companies afflicted by agency problems, managerial discretion, and overinvestment. We argue that, in the case of SOEs, the soft budget regime increases managerial discretion, facilitates collusion with vote-seeking politicians, and results in wasteful investment. Consistent with our predictions, we find that the regime switch disciplines SOE's investment behavior. Following a hardening of the budget constraint, managers lose discretion to indulge in collusion and overinvestment. J. Comp. Econ., June 2002 30(4), pp. 787–811. London School of Economics and Political Science, Houghton Street, London WC2A 2AE, United Kingdom; and CERIS–CNR, Institute for Economic Research on Firms and Growth, National Research Council, Via Avogadro, 8, 10121 Turin, Italy. © 2002 Association for Comparative Economic Studies. Published by Elsevier Science (USA). All rights reserved.Journal of Economic Literature Classification Numbers: E32, G31, G32, L32, M40.