Stationary measures for some Markov chain models in ecology and economics

Summary. Let continuous, exists in for x in . Let be an i.i.d. sequence from F and X₀ be a nonnegative random variable independent of . Let be the Markov chain generated by the iteration of random maps by . Such Markov chains arise in population ecology and growth models in economics. This paper studies the existence of nondegenerate stationary measures for {X_n}. A set of necessary conditions and two sets of sufficient conditions are provided. There are some convergence results also. The present paper is a generalization of the work on random logistics maps by Athreya and Dai (2000).Received: 20 March 2002, Revised: 4 December 2002, JEL Classification Numbers: C22, D9.The author wishes to thank Professor Mukul Majumdar and the referees for several useful suggestions.     

A general framework for the analysis of fiscal equalisation systems

This paper shows that, despite the existing diversity of models of fiscal equalisation, there is a common underlying structure that links all of them. To this end, a framework of analysis sufficiently general so as to encompass the main schemes present in the literature is developed. This allows to uncover the common features of these schemes and to identify more readily the origin and nature of their differences. The formal approach is complemented with a numerical simulation of the models considered. The paper also shows the usefulness of the approach for reform policy and suggests two new models.JEL Classification: H2, H7I would like to thank three anonymous referees for their helpful comments and suggestions to a previous draft of this article.     

A Theory of Menu Federalism: Decentralization by Political Agreement

This paper analyzes agreements between governments that determine the division of policy-making power between central and regional governments. Our analysis demonstrates that initial circumstances and political risks affect the degree of centralization that will be adopted, and that asymmetric forms of federalism are often consequences of ongoing negotiations between regional and central governments over the assignment of policy-making authority. We analyze three settings where gains from constitutional exchange may exist: (i) the under-centralized state, (ii) the over-centralized state, and (iii) the constitutional convention. In each case, an asymmetric form of federalism is the predicted outcome, although the degree of asymmetry differs according to starting point. Modern and historical examples are used to illustrate the relevance of our analysis.     

Job and worker flows in high adjustment cost settings

This paper analyses the relationship between the size of adjustment costs and the intensity of labor market flows. I argue that high adjustment costs inhibit adjustment to temporary shocks, leaving adjustment to long-lived shocks unchanged. Worker turnover is also reduced because of the negative impact that adjustment costs have on churning.Received: January 2002, Accepted: November 2002, JEL Classification: J23, J63I am grateful to the FCT for funding this research (research grant Praxis/PCSH/C/CEG/13/96), and to Pedro Portugal, Daniel Hamermesh and two anonymous referees for helpful comments on earlier versions of this paper. I thank the Department of Statistics at the Ministry of Labor for providing the data. CETE is supported by the FCT.     

On the performance of the Chow-Lin procedure for quarterly interpolation of annual data: Some Monte-Carlo analysis

Most of the countries of the OECD offer quarterly estimates of their national growth or of their Gross National Product. Official Statistical Agencies in western countries have to deal with the problem of estimating Quarterly National Accounts series congruently with Annual National Accounts. In Spain, the Instituto Nacional de Estadística uses the Chow-Lin disaggregation method, which is based on information provided by a group of high-frequency related variables, to estimate the quarterly components of National Accounts from annual components. In this paper, we analyse the relative quality of the estimates obtained through the Chow-Lin procedure, under different sets of hypotheses.JEL Classification: C15, C43, M40We are grateful to Maria Amparo Ripoll for her assistance. The authors also wish to thank three anonymous referees and an editor for their constructive suggestions and comments. This research was partially made during the stay of the first author at the Universidad Carlos III de Madrid. It has been partially supported by the research project DGCYT PB98-1460.     

A new century approach for alcohol screen in the insurance industry

Several recent studies point to the value of using combinations of biochemical markers for the identification of alcohol abuse. The Early Detection of Alcohol Consumption (EDAC) test uses a statistical method that combines the results of several routine laboratory tests to form a metabolic fingerprint for each subject. In this study, we evaluated the use of the EDAC test as a screening tool to assess heavy drinking in insurance applicants. The EDAC was calculated by linear discriminate function analysis using the results of 14 routine tests including liver enzymes, lipids, proteins, and blood sugars. We collected and analyzed 1680 random samples at Heritage Laboratories (Olathe, Kan). Alcohol Detection Services (Brookfield, Wis) and Millennium Strategies (Madison, Wis) collaborated in the data analysis and interpretation of laboratory tests results. Ninety-three percent of applicants showed a negative EDAC test. The 7% (n = 134) who screened positive for the EDAC test were then reflexed to carbohydrate deficient transferin (CDT) and whole blood associated acetaldehyde (WBAA). Sixteen percent (22/134) showed a positive confirmatory test. Among these 16% of subjects, 41% (9/22) showed no elevations in liver enzymes or HDL-C results. Four of these subjects were among the top one third with the highest elevations for the CDT test in the entire group and one of them was positive for both the CDT and WBAA tests. These results suggest that the EDAC screen may provide an efficient alternative screening tool for the identification of heavy alcohol consumption not HBA as it identifies applicants with both normal or abnormal liver enzymes and HDL-C.     

Environmental Conditions,Reservation Prices,and Time on the Market for Housing

A general analytical model to describe the impact of environmental disamenities on duration of sales is derived. A statistical technique to recover a sellers reservation price is proposed. An econometric procedure that consistently estimates market duration and a sellers reservation price is described. An application to the impact of highway noise on property values and market duration is presented. The estimation results show that, while highway noise has a significant negative impact on forming reservation prices and predicting sale prices, the noise effect on duration of sales is not statistically significant. Empirical evidence also shows a negative impact of market duration on reservation prices, which indicates an updating process for reservation prices over time.     

Organizational learning and the learning organization in health care

Learning is seen as a systems-level phenomenon that stays within the organization regardless of the "players" involved. However, this article reviews some of the history of organizational learning and the learning organization and makes a proposal for how health care organizations are becoming learning organizations.