The role of environmental factors in water utilities’ technical efficiency. Empirical evidence from Spanish companies

This article computes input-specific scores of technical efficiency for a sample of water utilities located in the southern Spanish region of Andalusia. In addition, differences in efficiency between different operating environments are investigated. Concerning the debate about ownership and efficiency, we find that privately owned companies outperform public utilities in their management of labour. Furthermore, technical efficiency is found to be greater among firms located in highly populated areas and for utilities providing water services to tourist municipalities. Finally, no empirical evidence supporting the greater technical efficiency of consortia of water utilities, a managerial strategy strongly encouraged by regional politicians, is found.     

On measuring speculative and hedging activities in futures markets from volume and open interest data

This article provides a critical assessment of the line of research that measures speculative and hedging activities in futures markets from volume and open interest data. It makes several contributions. First, a detailed theoretical analysis of the measures proposed in the previous literature as proxies for speculative activity clarifies the circumstances in which they fail, as well as the assumptions that have to be made, when they are used as intended. Second, we propose a new way of combining the volume and the open interest figures, which provides additional information regarding the type of trading activity that takes place in the market on a given date. Finally, we analyse empirically the basic statistical properties of all the ratios when they are applied to real data for some of the stock index futures contracts most actively traded in the world. This empirical analysis shows the diverse behaviour of the ratios when they are applied to a common sample of real data, which confirms our previous theoretical findings. Our contributions should be taken into account when any of the measures is used as a proxy for the relative importance of speculative demand in empirical analyses.     

What explains long memory in futures price volatility?

Long memory in futures price volatility is a well-documented stylized fact with implications for market efficiency, risk management, forecasting and option pricing bias. The implications of long-memory differ, however, based on whether it is of a ‘fractional’ or of a ‘stochastic’ type. The aims of this article are to determine, in the case of agricultural commodity futures data, which type better describes price volatility and also to evaluate several competing explanations for findings of long memory. The evidence presented here finds little support for three out of four potential explanations, namely, excessive noise in the volatility measure, bias in the long-memory estimator and understated SEs of the long-memory parameter. For the data considered, price volatility appears to be most likely generated by a nonfractional long-memory process such as a stochastic break or stochastic unit root.     

INFERENCE FOR DOMINANCE RELATIONS

The use of partial orders has been popularized as a way to conduct social evaluations using only minimal normative assumptions. Generically, this process involves comparing continuously indexed curves that are uniquely determined by the cumulative distributions of the individual attributes under study. In the literature on income poverty and inequality, for example, pairwise comparisons of entire income distributions and their respective Lorenz curves are routinely performed in order to characterize rankings of poverty, inequality, and welfare. In this article, we focus on the inferential problem that arises whenever such comparisons are made in the absence of census data. Statistical inference in these situations is particularly complex due to the fact that comparing curves invariably gives rise to four possibilities: the true population curves are equal, the first curve lies below the second, the second lies below the first, or the curves cross. To address this four‐decision problem, we introduce a two‐stage test that has good power and fine control over misclassification error rates.     

Idea Competitions under scrutiny: Acquisition,intelligence or public relations mechanism?

Idea Competitions (ICs) are becoming a popular mechanism chosen by firms to perform Open Innovation. They are a way to engage with external sources of knowledge such as individual entrepreneurs and small firms who are asked to submit ideas and compete for a prize. However, little is known about the success of ICs as acquisition mechanisms. The researchers conducted interviews in five multinational companies to evaluate the effects of using ICs as an acquisition mechanism. Although still preliminary, the results of this study show that the success of ICs as an acquisition mechanism remains uncertain because their output (i.e. the number of ideas acquired) is often low compared to the input (i.e. the number of ideas submitted) and effort required to run them (e.g. to vet ideas). Across the cases observed, ICs appear to be more successful at identifying and acquiring early-stage ideas, particularly those outside the current business focus. The study shows that ICs deliver other functional benefits such as improved intelligence and public relations and that these need to be considered as part of the evaluation of the IC's success. The paper concludes by discussing the conditions in which ICs are implemented and the implications for Open Innovation theory.     

The NBA and the influx of international basketball players

The determinants of salaries for professional athletes in the National Basketball Association (NBA) are examined to investigate how international athletes have fared relative to athletes trained in the United States. It is found that international basketball players were paid a large premium above other players of similar skills and characteristics for the 1996–97 and 1997–98 seasons, after which the premium disappeared. This temporary premium is likely attributable to a?‘winner's curse’?experienced by NBA teams before investing significant resources in scouting and evaluating international players.     

Time-specific disturbances and cross-sectional dependency in a small-sample heterogeneous panel data unit root test

In their seminal work, Im et al. (1997 Im, KS, Pesaran, MH and Shin, Y. 1997. Testing for unit roots in heterogeneous panels. 1997. Working paper, Department of Applied Economics, University of Cambridge. Mimeographed [Google Scholar], 2003 Im, KS, Pesaran, MH and Shin, Y. 2003. Testing for unit roots in heterogeneous panels. Journal of Econometrics, 115: 53–74. [Crossref], [Web of Science ®] , [Google Scholar]) suggested that time series for several cross-sectional units could be used to increase the power of the Dickey--Fuller unit root test. They argued that when cross-sectional correlation is a problem that can be modelled by a time-specific factor, demeaning across the cross-sectional units can solve the problem. In this study, this proposition is proven valid, but it is also shown that previously supplied standardizing moments are inappropriate when the number of cross-sections are small, causing size to differ from the significance level. To correct this size distortion, the current paper supplies response surface parameters that can be used to obtain moments that are valid when a time-specific factor suffices for modelling cross-sectional correlation in the heterogeneous panel data unit root framework. The correct size of the panel data unit root test comes at the cost of a somewhat lower power against a stationary alternative.     

Options-based forecasts of futures prices in the presence of limit moves

The reported analysis examines a simultaneous estimation option-based approach to forecast futures prices in the presence of daily price limit moves. The procedure explicitly allows for changing implied volatilities by estimating the implied futures price and the implied volatility simultaneously. Using futures and futures options data for three agricultural commodities, it is found that the simultaneous estimation approach accounts for the abrupt changes in implied volatility associated with limit moves and generates more accurate price forecasts than conventional methods that rely on only one implied variable.