Clustering to reduce regional heterogeneity: A spanish case-study

Statistical methods of dimension reduction and classification are used to obtain homogeneous local-area clustering with regard to the most relevant demographic parameters. The dimension reduction is conducted in two stages using Principal Component Analysis and a modified k-mean procedure is proposed to determine the final clusters. This clustering will be useful in future demographic studies at a local level, in particular to obtain forecasts of demographic rates and population projections. The region of Castile and León in Spain is used to illustrate the method. A Poisson model is used to explore the advantages of the new clustering over the more conventional classification based on provinces.     

The Impact of Overeducation on Wages of Recent Economic Sciences Graduates

Social Indicators Research - United Nations Development Program presented the Human Development Index for ranking the countries with regard to three dimensions, namely being knowledgeable, a long...     

Expected utility from additive utility on semigroups

In the present paper we study the framework of additive utility theory, obtaining new results derived from a concurrence of algebraic and topological techniques. Such techniques lean on the concept of a connected topological totally ordered semigroup. We achieve a general result concerning the existence of continuous and additive utility functions on completely preordered sets endowed with a binary operation ``+', not necessarily being commutative or associative. In the final part of the paper we get some applications to expected utility theory, and a representation theorem for a class of complete preorders on a quite general family of real mixture spaces.     

Web Survey Design: Paging versus Scrolling

A key choice in the design of Web surveys is whether to placethe survey questions in a multitude of short pages or in longscrollable pages. There are advantages and disadvantages ofeach approach, but little empirical evidence to guide the choice.In 2003 we conducted a survey of over 21,000 undergraduate students.Ten percent of the 10,000 respondents were directed to the scrollableversion of the survey, containing a single form for each ofthe major sections. The balance was assigned to the paging version,in which questions were presented to be visible without scrolling.The instrument contained a maximum of 268 possible questions,including topics that varied in sensitivity and desirability.The survey also permitted comparison of the effect of skip patternsby implementing skip instructions and hyperlinks in the scrollabledesign, and also recorded time at the end of each of the fivetopical sections. Differences between designs are evaluatedin terms of various forms of nonresponse, univariate and bivariatemeasurement properties, and proxies for respondent burden.     

The Impact of Corporate Reputation on Firm Risk: A Panel Data Analysis of Spanish Quoted Firms

Researchers have traditionally addressed the influence of corporate reputation on firm performance, but have not considered the influence of corporate reputation on firm risk. This research develops hypotheses regarding the opposing influence of corporate reputation on a firm's systematic risk, unsystematic risk and total risk, as well as the moderation effect of firm size and industry concentration. Using a panel data method, these relationships are analysed, controlling for the effects of endogeneity, for a sample of Spanish quoted firms in the period 2001–2007. Specifically, two complementary analyses are performed. The first distinguishes firms included and not included in the MERCO index of the most reputable firms. The second analyses the impact of corporate reputation for the sub‐sample of most reputable firms. Being reputable reduces a firm's unsystematic risk and total risk, but increases systematic risk. In addition, firm size weakens these influences of corporate reputation on firm risk. However, among the most reputable firms, differences in reputation score have a lower effect on risk. Specifically, the corporate reputation level only influences firm unsystematic risk. It seems that what matters is not the degree of corporate reputation, but whether being or not being reputable is the question in terms of risk.     

The Union Effect on Wages in Chile: A Two‐Stage Approach Using Panel Data

We estimate the union effect on wages in Chile to be between 18 and 24 per cent. We follow a two‐stage procedure that allows us to correct the endogeneity of union status and to separate true from spurious dependence, by exploiting the union history of individuals using panel data. We find evidence of comparative‐advantage sorting in union status, strong true state dependence and a re‐distributional effect of union membership (i.e. wage gains from unionization are larger for lower‐wage earners).     

Nonparametric estimation of survival functions for doubly censored observations when the lifetime hazard rate is proportionally related to the censoring hazard rates

Let T, X and Y be non-negative random variables, where T is the time of occurrence of an event of interest, X and Y being the lefl and right censoring variables respectively.

In this paper we propose a nonparametric estimator of the survival function, ST, when T, X and Y are supposed to be independent and their corresponding hazard rates are proportionally related. In this way, our results extend Ebrahimi's work (1985) to the doubly censored data case.     

Evaluation of the Productivity Decrease Risk Due to a Future Increase in Tropical Cyclone Intensity in Japan

A number of scientists have recently conducted research that shows that tropical cyclone intensity is likely to increase in the future. This would result in an increase in the damage along with a decrease in economic productivity due to precautionary cessation of the economic activity of the affected areas during the passage of the cyclone. The economic effect of this stop in economic activity is a phenomenon that has not received much attention in the past, and the cumulative effect that it can have on the Japanese economy over the next 75 years has never been evaluated. The starting point for the evaluation of the economic risks is the change in the patterns of tropical cyclone intensity suggested by Knutson and Tuleya.⁽ 1 ⁾ The results obtained show how a significant decrease in the overall productivity of the country could be expected, which could lower GDP by between 6% and 13% by 2085.     

Variance reduction in the study of a test concerning the behrens-fisher problem

A simulation case study illustrating the implementation of a variance reduction technique appropriate for dichotomous response variables is presented. In this simulation study, concerning the power of the Cochran and Cox test for the equality of means under possibly unequal variances, variance reductions of around 80% or more are obtained. More importantly, a known property of the Cochran and Cox, its conservative character, is detected thanks to the use of variance reduction.