Short Run Constraints and the Increasing Marginal Value of Time in Recreation

Leisure activities such as local recreation trips usually take place in discrete blocks of time that are surrounded by time devoted to other commitments. It can be costly to transfer time between blocks to allow for longer outings. These observations affect the value of time within those blocks and suggest that traditional methods for valuing time using labor markets miss important considerations. This paper presents a new model for time valuation that uses non-employment time commitments to infer the shadow value of time spent in recreation. A unique survey that elicited revealed and stated preference data on household time allocation is used to implement the model. The results support the conclusion that there is an increasing marginal value of time for recreation as the trip length increases.     

Understanding perpetual R&D races

This paper presents an experimental study of dynamic indefinite horizon R&D races with uncertainty and multiple prizes. The theoretical predictions are highly sensitive: small parameter changes determine if we should expect technological competition, and if so whether it is sustained, or if the market converges into one with entrenched leadership and lower aggregate R&D. The subjects’ strategies are far less sensitive. In most of the treatments, the R&D races tend to converge to entrenched leadership. We propose and apply a quantal response extension of Markov perfection that is qualitatively and largely quantitatively consistent with the experimental observations.     

Technology assessment: Impact of high-tech engineering research on energy consumption

A technology assessment (TA) program was launched in Switzerland in 1991. One project in the series of pilot projects was meant to assess the impact of so-called LESIT technologies on energy consumption. (LESIT was a priority research program and a German acronym for power electronics, systems and information technology.) In this paper the institutional environment, applied methods and main results of the TA study are summarised. One of the questions that arose was whether it is reasonable to expect a high-tech engineering research program to serve any societal goals other than the more immediate technical and economic goals the research partners in university and industry are accustomed to follow. It was found that without special efforts this expectation was not realistic. Politically desirable goals are best served when enough emphasis, time, and money are given to the process of bringing together research partners from academia and industry who all have a (self-serving) interest in furthering the politically desirable goal and then support their collaboration.     

Understanding forecast failure of ESTAR models of real exchange rates

The forecast performance of the empirical ESTAR model of Taylor et al. (2001) is examined for 4 bilateral real exchange rate series over an out-of-sample evaluation period of nearly 12?years. Point as well as density forecasts are constructed, considering forecast horizons of 1 to 22 steps head. The study finds that no forecast gains over a simple AR(1) specification exist at any of the forecast horizons that are considered, regardless of whether point or density forecasts are utilised in the evaluation. Non-parametric methods are used in conjunction with simulation techniques to learn about the models and their forecasts. It is shown graphically that the nonlinearity in the conditional means (or point forecasts) of the ESTAR model decreases as the forecast horizon increases. The non-parametric methods show also that the multiple steps ahead forecast densities are normal looking with no signs of bi-modality, skewness or kurtosis.     

Wage inequality in a developing country: decrease in minimum wage or increase in education returns

In this paper we analyze the increase in wage inequality observed in the Uruguayan labour market during the last decade, by studying how the changes in minimum wage and returns to education affected the wage structure. Although in most developed countries a significant proportion of the increase in wage inequality is explained by a fall in the real minimum wage, this is not the case for the Uruguayan labour market. We observe that returns to education increased significantly, which could explain the increase of wage dispersion by its effects on the upper tail of the wage distribution. To derive these conclusions we follow a parametric and nonparametric quantile regression approach.     

Probability and quantile estimation from individually micro-aggregated data

Micro-aggregation is a frequently used strategy to anonymize data before they are released to the scientific public. A sample of a continuous random variable is individually micro-aggregated by first sorting and grouping the data into groups of equal size and then replacing the values of the variable in each group by their group mean. In a similar way, data with more than one variable can be anonymized by individual micro-aggregation. Data thus distorted may still be used for statistical analysis. We show that if probabilities and quantiles are estimated in the usual way by computing relative frequencies and sample quantiles, respectively, these estimates are consistent and asymptotically normal under mild conditions.     

A new fluctuation test for constant variances with applications to finance

We present a test to determine whether variances of time series are constant over time. The test statistic is a suitably standardized maximum of cumulative first and second moments. We apply the test to time series of various assets and find that the test performs well in applications. Moreover, we propose a portfolio strategy based on our test which hedges against potential financial crises and show that it works in practice.     

A buyer's perspective on collaborative versus transactional relationships

This research examines collaborative and transactional relationships in buying firms to determine whether collaborative relationships offer greater benefits than transactional relationships, and to ascertain which relational factors drive satisfaction and performance for both collaborative and transactional relationship types. Factor analysis, t-tests and step-wise regression were used to analyze data from a survey of buying firms. Results show that collaborative relationships offer higher levels of satisfaction and performance than transactional relationships. Satisfaction factored into two separate constructs: satisfaction with the relationship and satisfaction with the results. Of the relational factors examined, trust is the most important predictor of performance and satisfaction with the relationship regardless of the type of relationship examined.     

Multidimensionales Verfahren zur Bestimmung des Regelleistungsbedarfes unter Berücksichtigung von Unsicherheiten

One of the most crucial constraints in operation of electrical power supply systems is the permanent balance between generation and load. Reserve power is held ready to be able to keep this balance also in case of the occurrence of unpredictable events like power plant outages or inevitable deviations of power injections from their predicted values. At this, the allocation of operating reserves is in the field of conflict between level of reliability and cost effectiveness. The amount of reserve generation capacity required in a control area heavily depends on prediction quality which constitutes the need for high quality predictions. This article is about the influence of prediction quality on the amount of reserve generation capacity required in a control area. The algorithms for the assessment of required reserve generation capacity known from literature use the variation calculus technique to account for the aforementioned unpredictable events and prediction errors. In this article, an extension to a convolution-based method is presented in which the uncertainties of the predictions are expressed using intervals. Each parameter is represented by an independent dimension, assuming statistical independence among them. This allows the distinct analysis of each parameter’s influence on the amount of required reserve generation capacity. In addition, two methods for the visualization of the multi-dimensional results are presented, allowing a comprehensive analysis of the parameters’ influences. Standard distribution functions are used to represent the parameters for the simulation and the results are shown as probability density functions of possible imbalances. Based on forecasts of the development of conventional power plants and regenerative generation in the years 2020, 2030 and 2040, the required control power of the future German transmission system is calculated. Influences and dependencies are identified with the extended convolution-based method.     

Directional duality theory Directional duality theory

In this paper we introduce a complete duality theory based on directional distance functions. This duality theory parallels the duality theory based on radial distance functions in Färe and Primont (1995).