Why and how to use vector autoregressive models for quality control: the guideline and procedures

While quality control on multivariate and serially correlated processes has attracted research attentions, a number of very detailed problems need to be overcome in order to construct practical control charts. We suggest guidelines for construction of control charts based on vector autoregressive (VAR) residuals. We discuss why VAR model is reasonable for real processes in nature, the use of VAR models to approximate multivariate serially correlated processes, residual estimation, selecting the number of variables, and selecting appropriate orders, among other issues. In addition, we illustrate an example employing VAR techniques to approximate a multivariate process previously examined and construct a control chart to monitor residuals. Last, we illustrate the potential development and use of the VAR residual chart to assist quality control and improvement.     

Posting,quoting, and replying: a comparison of methodological approaches to measure communication ties in web forums

Active involvement in discussion-based communities is nowadays a firm part of people’s online activities. The measurement of communication ties and networks between contributors to such domains is thus becoming a relevant research question in social sciences. However, especially in web forums, very often almost no direct relational information exists that would indicate the presence of communication ties among contributors. In contrast with the reply-to structure of Usenet newsgroup or mailing list conversations that contain explicit relational information created by the contributors, some web forums only enable participants to add new posts to threads or to quote preceding posts in threads. When discussions emerge, it is difficult to identify who is replying to whom. Drawing on the social network studies dealing with the conversational patterns in Usenet and web forums, this paper presents an alternative approach to identifying the ties between authors of posts. Several assumptions are discussed, and different measures are developed and empirically evaluated. The findings provide a starting point for the development of a standardized methodology for studying social networks in online communities where only limited direct information about communication ties is available.     

Cost Uncertainty and Unilateral Abatement

Unilateral abatement is sometimes advocated in order to set a good example that will make other countries follow. The aim of this paper is to investigate whether existence of correlated cost uncertainty provides an incentive for a country to undertake unilateral abatement. The theoretical model is driven by two main mechanisms; first, a learning effect, as the follower country might reduce its risk premium as it can observe the cost level in the leader country. Second, there is the public good effect, i.e., the marginal benefit of abatement declines when abatement is a public good and other countries contribute to pollution reductions. Results shows that unilateral abatement would be efficient in reducing uncertainty about the unit costs of abatement if a country with low cost uncertainty would undertake abatement first, while a country with initially high cost uncertainty would follow. However, countries may prefer to act simultaneously because of the larger uncertainties that are inherent in a sequential game.      

Price discrimination and efficient matching

This paper considers the problem of a monopoly matchmaker that uses a schedule of entrance fees to sort different types of agents on the two sides of a matching market into exclusive meeting places, where agents randomly form pairwise matches. We make the standard assumption that the match value function exhibits complementarities, so that matching types at equal percentiles maximizes total match value and is efficient. We provide necessary conditions and sufficient conditions for the revenue-maximizing sorting to be efficient. These conditions require the match value function, modified to incorporate the incentive cost of eliciting private type information, to exhibit complementarities in types.JEL Clalssification Numbers C7, D4We thank Jonathan Levin, Tracy Lewis, and the seminar audience at University of California at Los Angeles, University of British Columbia, Duke University, and 2003 Econometric Society North American Summer Meeting for comments and suggestions. We are also grateful for helpful suggestions from the referees and the Editor     

Unemployment dynamics in an OLG economy with public pensions

Pension benefits in old age establish a disincentive to save in youth, thereby yielding lower levels of capital stock and the wage rate. As a result, the trade union has an incentive to change the composition of its two targets: employment and the wage rate. This paper develops a model that includes employment effects of public pensions via capital accumulation and union wage setting. Within this framework, we consider how contribution rates to the pension system influence the level and time path of the unemployment rate. It is demonstrated that (1) a higher contribution rate results in a lower unemployment rate, and (2) the economy with a high (low) contribution rate experiences monotone convergence towards (oscillatory convergence towards or a period-2 cycle around) the steady state. The author would like to thank an anonymous referee, Kazutoshi Miyazawa, and seminar participants at Osaka University for their useful comments and suggestions, and Masako Ikefuji and Hiroaki Yamagami for their research assistance. Financial support from the Japan Society for the Promotion of Science (JSPS) through a Grant-in-Aid for Young Scientists (B) (No.17730131), the Asahi Glass Foundation, the Japan Economic Research Foundation and the 21st Century COE Program (Osaka University) is gratefully acknowledged. All remaining errors are mine.     

Amended final-offer arbitration over an uncertain value: A comparison with CA and FOA

Arbitration is increasingly employed to resolve disputes. Two arbitration mechanisms, conventional arbitration (CA) and final-offer arbitration (FOA) are commonly utilized, but previous theoretical and empirical research has found that they are unsatisfactory. Several alternative mechanisms have been proposed, but ultimately laboratory research has found that they do not offer an improvement. An exception is amended final-offer arbitration (AFOA), which not only has desirable theoretical properties but also has been demonstrated to outperform FOA in the laboratory. This study provides a direct laboratory comparison of AFOA with CA. Also, by utilizing an environment with an uncertain payoff to one of the parties, this study tests the robustness of AFOA’s performance relative to FOA. The results indicate that AFOA does outperform FOA, but that AFOA is only weakly better than CA. JEL Classification C7, C9, J5, K4     

Repeated Dichotomous Choice Formats for Elicitation of Willingness to Pay: Simultaneous Estimation and Anchoring Effect

Repeated dichotomous choice contingent valuation data are generated from responses to a succession of binary questions regarding alternative prices for an environmental good. In this paper we propose a simultaneous equation model that allows for endogeneity and error correlation across the responses at each stage of the bidding process. The model allows us to study the evolution of anchoring effects after the second dichotomous choice question. Estimation involves the Bayesian techniques of Gibbs sampling and data augmentation, and the application focuses on the preservation value of a natural area. The results for a data set involving up to four successive dichotomous choice questions show that restricted multiple-bounded models are rejected by the data with the general model. In addition, willingness to pay tends to stabilize after the second stage in the elicitation process for the general unrestricted model. When taking anchoring effects into consideration, it is revealed that individuals’ responses in the latter stages are influenced by the sequence of bid prices offered in earlier questions. Nevertheless, they do not have a significant effect on welfare estimates.      

Are we nice(r) to nice(r) people?—An experimental analysis

We experimentally investigate whether individuals can reliably detect cooperators (the nice(r) people) in an anonymous decision environment involving “connected games.” Participants can condition their choices in an asymmetric prisoners’ dilemma and a trust game on past individual (their partner’s donation share to a self-selected charity) and social (whether their partner belongs to a group with high or low average donations) information. Thus, the two measures of niceness are the individual donation share in the donation task, and the cooperativeness of one’s choice in the two games. We find that high donors achieve a higher-than-average expected payoff by cooperating predominantly with other high donors. Group affiliation proved to be irrelevant. Electronic Supplementary Material Supplementary material is available in the online version of this article at . JEL Classification C91, C72, D3     

The Influence of Socioeconomic Factors on Economic Growth

The main goal of this paper is to analyse the relationship between social capital and economic growth taking into account the role of fiscal policy from theoretical and empirical points of view. To achieve this goal, “Human Capital and Public Capital Effects on Economic Growth” is focused on the effects of two traditional factors: human capital and public capital effects on economic growth. “Social Capital Effects on Economic Growth” considers qualitative variables introducing some socioeconomic effects on economic growth process analysis. In this case, social capital the main variable will be considered. “Empirical Analysis,” an empirical analysis is developed considering the case of European countries prior to the EU enlargement. Finally, in Conclusions,” the main conclusions will be resumed.