A Geometrical Interpretation of Collinearity: A Natural Way to Justify Ridge Regression and Its Anomalies

Justifying ridge regression from a geometrical perspective is one of the main contributions of this paper. To the best of our knowledge, this question has not been treated previously. This paper shows that ridge regression is a particular case of raising procedures that provide greater flexibility by transforming the matrix X associated with the model. Thus, raising procedures, based on a geometrical idea of the vectorial space associated with the columns of matrix X , lead naturally to ridge regression and justify the presence of the well-known constant k on the main diagonal of matrix X ^′ X . This paper also analyses and compares different alternatives to raising with respect to collinearity mitigation. The results are illustrated with an empirical application.     

Why some firms adopt telecommuting while others do not: A contingency perspective

Using a contingency perspective and data from 122 CEOs of Spanish firms, this paper examines what makes a firm likely to adopt telecommuting. We hypothesized that employer adoption of telecommuting would depend on organizational constraints (age and size of the firm), the international composition of the workforce, and the top executives' leadership style. In turn, we argue that firms adopting telecommuting would emphasize outcome‐based control systems. Our empirical evidence showed that telecommuting correlated with small organizational size, a high proportion of international employees, and variable compensation. A contingent reward leadership style at the top moderated the effects of firm age and internationalization on the adoption of telecommuting. © 2009 Wiley Periodicals, Inc.     

Does land use planning shape regional economies? A simultaneous analysis of housing supply,internal migration and local employment growth in the Netherlands

Why has job growth over the past decades been weaker in the Dutch Randstad area than in surrounding regions? In a simultaneous equations analysis, we find that employment has adjusted to the regional supply of labour. Net internal migration was predominantly determined by regional housing supply, and not by employment growth. Growth of the regional housing stock appeared insensitive to changes in the number of people and jobs. This lack of responsiveness to demand conditions is consistent with the presence of strong restrictions on residential development near the main Dutch cities, suggesting that the current regional distribution of economic activity in the Netherlands reflects land use planning decisions.     

Openness of the economy,terms of trade,and arms

It is estimated that world military spending in 2011 amounted to over 2.5% of the world's Gross Domestic Product (GDP). This corresponds to a spending of $233 per person in the world at 2010 constant prices, an amount close to the GDP per capita of the poorest country in the world. Therefore, it is important for economists to understand the allocation of resources to this sector of the economy. I present a model that explores the determinants of a country's level of military spending. I show how greater gains from trade can lead to greater military expenditures to protect them. It is also found that expansion in the demand for a country's tradable commodities, that is, an improvement in that country's terms of trade, will impact defense spending. Several other propositions emerge from the model which are then empirically tested using both pooled and time series data. The statistical results support the model's propositions.     

ROSA,ROSAE, ROSIS: modelling a regional open sectoral innovation system

The literature on territorial innovation modes has identified the development of a diverse set of innovation systems at multiple levels of analysis. However, there are certain gaps that do not allow their adaptation to the particularities of certain territories. Despite the multiple concepts related to innovation systems approach, the state of the art does not yet provide a useful analytical approach for a deep and comprehensive characterization of territories with a high sectoral and technological specialization. This paper introduces an analytical framework based on a regional open and sectoral innovation system, which is qualitatively tested in the Durango County (Spain). The aim of this paper is to introduce a subtype of innovation system that meets the requirements and needs of a located micro-territory with a high level of sectoral specialization.     

Estimation of Asymmetric Stochastic Volatility Models: Application to Daily Average Prices of Energy Products

Energy supply and demand, and as a consequence energy prices, are likely to represent one of the biggest challenges of the 21st century. Commodity markets exhibit increased volatility when there is little or no underutilized supply capability to meet natural fluctuations in demand. In the case of energy markets, the large capital requirements and significant lead times associated with energy production and delivery make them more susceptible to the imbalances in supply capability and demand. Energy price volatility has destructive impact on market agents, and this impact is intensified when the prices exhibit asymmetric volatility. This article pursues two aspects of the issue. First we consider general aspects, especially the asymmetric pattern of volatility of daily returns of different types of energy products. Then, we analyze the behaviour of daily returns by using traditional models of volatility that include AGARCH, TGARCH, EGARCH, and ARSV strategies, as well as a threshold asymmetric autoregressive stochastic volatility (TA-ARSV) model that we propose. The energy products considered in this analysis are probably the most relevant energy products for the economic activity of the nations and the economic relations between countries: Crude Oil (OPEC reference basket and London Brent index), Gasoline, Natural Gas, Butane, and Propane. We use spot prices and the time reference ranges from 1986–1993 to 2009 depending on the product.     

A STRUCTURAL RISK‐NEUTRAL MODEL FOR PRICING AND HEDGING POWER DERIVATIVES

We develop a structural risk‐neutral model for energy market modifying along several directions the approach introduced in Aïd et al. In particular, a scarcity function is introduced to allow important deviations of the spot price from the marginal fuel price, producing price spikes. We focus on pricing and hedging electricity derivatives. The hedging instruments are forward contracts on fuels and electricity. The presence of production capacities and electricity demand makes such a market incomplete. We follow a local risk minimization approach to price and hedge energy derivatives. Despite the richness of information included in the spot model, we obtain closed‐form formulae for futures prices and semiexplicit formulae for spread options and European options on electricity forward contracts. An analysis of the electricity price risk premium is provided showing the contribution of demand and capacity to the futures prices. We show that when far from delivery, electricity futures behave like a basket of futures on fuels.     

A note on how to measure hubbing practices in airline networks

Benefits and costs associated to hubbing practices of airlines are still subject to much debate. In the previous literature, some standard spatial concentration indices have been proposed to measure it. However, we show that these indices are “ill-defined” because they do not take into account the salient characteristic of hubbing: connecting passengers. The purpose of this research is to present a new methodology which avoids the pitfalls of other methods. Our new methodology also analyzes the level of concentration of the connecting passengers studying two different dimensions: hub airports and routes. Finally, we apply our methodology to some US carriers.