On dichotomous choice contingent valuation data analysis: Semiparametric methods and Genetic Programming

The aim of this paper is twofold. Firstly, we introduce a novel semiparametric technique called Genetic Programming to estimate and explain the willingness to pay to maintain environmental conditions of a specific natural park in Spain. To the authors’ knowledge, this is the first time in which Genetic Programming is employed in contingent valuation. Secondly, we investigate the existence of bias due to the functional rigidity of the traditional parametric techniques commonly employed in a contingent valuation problem. We applied standard parametric methods (logit and probit) and compared with results obtained using semiparametric methods (a proportional hazard model and a genetic program). The parametric and semiparametric methods give similar results in terms of the variables finally chosen in the model. Therefore, the results confirm the internal validity of our contingent valuation exercise.     

我国调整劳资关系的三方协商机制存在的问题及对策分析

三方协商机制是调整劳资关系的重要机制,并已成为许多国家的一种社会对话方式。我国调整劳资关系的三方机制建立时间短,还存在协商主体代表性不足、角色定位不准和协商范围窄等问题,需要进一步完善才能发挥三方机制应有的作用。     

Modelling superannuation fund management function as a two-stage process for overall and stage-level performance appraisal

We assess superannuation fund performance in a multi-dimensional framework by conceptualizing its management function as a serially linked two sub-process; operational management (OM) and portfolio management (PM). The procedure that we adopt is data envelopment analysis (DEA). We express overall efficiency as a weighted average of the two sub-process efficiencies and assess overall efficiency conditional on their relative importance. We demonstrate application of our model using a sample of Australian superannuation funds. By appraising performance in two sample periods; crisis (2008) and relatively non-crisis (2014), we show that some findings of previous studies may be explained further through the proposed multi-stage framework. The best overall performer in 2008 is public sector funds and in 2014 it is corporate funds. Decomposition of overall efficiency reveals that public sector funds, on average, outperform all other fund categories in OM. However, no specific fund category dominates PM performance in both assessment periods. The driving force behind the observed inverse association between superannuation fund size and performance appears to be PM performance. Number of investment options offered is not associated with overall, OM and PM performance. Here, we demonstrate that performance appraisal from different aspects of management provide insightful information to superannuation fund managers.     

A Direct Approach to the Discounted Penalty Function

Abstract

This paper provides a new and accessible approach to establishing certain results concerning the discounted penalty function. The direct approach consists of two steps. In the first step, closed-form expressions are obtained in the special case in which the claim amount distribution is a combination of exponential distributions. A rational function is useful in this context. For the second step, one observes that the family of combinations of exponential distributions is dense. Hence, it suffices to reformulate the results of the first step to obtain general results. The surplus process has downward and upward jumps, modeled by two independent compound Poisson processes. If the distribution of the upward jumps is exponential, a series of new results can be obtained with ease. Subsequently, certain results of Gerber and Shiu [H. U. Gerber and E. S. W. Shiu, North American Actuarial Journal 2(1): 48–78 (1998)] can be reproduced. The two-step approach is also applied when an independent Wiener process is added to the surplus process. Certain results are related to Zhang et al. [Z. Zhang, H. Yang, and S. Li, Journal of Computational and Applied Mathematics 233: 1773–1 784 (2010)], which uses different methods.     

New panel results on cointegration of international health expenditure and GDP

This article tests for existence of cointegration between health expenditure and GDP using data from 25 OECD countries for the period 19607ndash;1997. The empirical modelling is based on a heterogeneous bivariate vector error correction panel model that allows for trending data as well as intercepts and trends in the cointegrating relations. Univariate country-by-country and panel unit root tests generally fail to reject the null of a unit root in the health expenditure and GDP variables. Country-by-country results based on the Johansen multivariate likelihood-based inference indicate somewhat mixed results on country-specific cointegration with a rank of one found for 12 countries and a rank of zero for the remaining 13 countries. Application of a new panel test for cointegration rank with higher power than the individual tests indicates that health expenditure and GDP are cointegrated around linear trends.     

A model for estimating fish population and optimal fishing effort in lakes and rivers

We developed a model for estimating the fish population for various species in lakes and rivers. Our estimation focuses, in its first step, on fish species that breed outside the lake. Using the annual outside supply of fingerlings, natural survival rate and reported amounts of fish caught, we estimated fish stock. Given the estimated stock for fish bred outside the lake, we can evaluate the catch rate. Assuming equal catch rates for other species, and given the amount caught for each species, we are able to evaluate each species stock. Using the proposed technique, we evaluated various species stocks in the Sea of Galilee (Lake Kinneret) in Israel. Using our suggested technique for evaluating fish stock, we calculated the optimal effort of fishing needed for maximizing steady state profit of the fishers.