Sparse Partial Least Squares in Time Series for Macroeconomic Forecasting

Factor models have been applied extensively for forecasting when high‐dimensional datasets are available. In this case, the number of variables can be very large. For instance, usual dynamic factor models in central banks handle over 100 variables. However, there is a growing body of literature indicating that more variables do not necessarily lead to estimated factors with lower uncertainty or better forecasting results. This paper investigates the usefulness of partial least squares techniques that take into account the variable to be forecast when reducing the dimension of the problem from a large number of variables to a smaller number of factors. We propose different approaches of dynamic sparse partial least squares as a means of improving forecast efficiency by simultaneously taking into account the variable forecast while forming an informative subset of predictors, instead of using all the available ones to extract the factors. We use the well‐known Stock and Watson database to check the forecasting performance of our approach. The proposed dynamic sparse models show good performance in improving efficiency compared to widely used factor methods in macroeconomic forecasting. Copyright © 2014 John Wiley & Sons, Ltd.     

Measuring the cost of liquidity in agricultural futures markets: Conventional and Bayesian approaches

Estimating the cost of liquidity in agricultural futures markets is challenging because bid‐ask spreads are usually not observed. Based on an ability to reflect simulated data from Roll's spread model, we assess the effectiveness of conventional and Bayesian bid‐ask spread estimators under different market conditions. Conventional serial covariance and absolute price change spread estimators appear to be biased. Hasbrouck's Bayesian estimator generates small costs of liquidity whose values depend on the correlation and noise in the data. The absolute value Bayesian estimator is precise and works well under conditions of high levels of noise and correlation usually found in agricultural futures markets. Using data from live cattle (LC) and lean hog (LH) contracts, we find similar patterns of performance that produce economically meaningful cost of liquidity differences.     

What hinders innovation performance of services and manufacturing firms in Mexico?

Barriers to innovation are heterogeneous, of financial and non-financial nature. The importance of barriers to innovation and their actual influence on innovation depend on firms’ characteristics such as sectoral affiliation, technological behavior and their response to perceived obstacles to innovation. Firms either continue to engage in innovation, or they avoid the activity altogether. This paper explored the nature and perceived importance of the obstacles to innovation that firms confront, in a developing-country context; we build on survey data about firms in Mexico. Our findings suggest that two kinds of policy interventions should help offset a firm’s perception of barriers to innovation. On the one hand, policies should enhance the innovation capacity of firms interested in innovation; on the other hand, policies need to tackle factors that reduce the interest of firms in innovation. Policies that boost demand for locally generated innovations would assist in achieving both these goals.     

Efficiency of travel agencies: A case study of Alicante,Spain

This study analyses the relative efficiency of 22 travel agencies of similar characteristics based in Alicante (Spain). This analysis is carried out using the Data Envelopment Analysis (DEA) technique and smoothed bootstrap. Following the analysis, possible lines of action that the agencies can take in order to improve their efficiency in the future are provided. Finally, using the Mann Whitney U Test, the relationship, or lack thereof, between the levels of efficiency of these agencies and their ownership type, location and level of experience is examined.     

Knowledge acquisition and corporate entrepreneurship: Insights from Spanish SMEs in the ICT sector

The contingent perspective on the corporate entrepreneurship–performance relationship has focused mainly on the influence of factors either environmental or internal to the organization. Only recently have researchers turned their attention to the relational context and specifically to inter-organizational alliances’ potential to influence this relationship. Our paper analyzes how knowledge acquisition from alliances affects the corporate entrepreneurship–performance relationship in a sample of Spanish SMEs from the Information and Communication Technology sector (ICT). The results obtained show that both corporate entrepreneurship and knowledge acquisition have a positive influence on performance but that the moderating effect of knowledge acquisition on the relationship between corporate entrepreneurship and performance is negative and it varies depending on the level of knowledge-based resources of the firm.     

Controlling the Urban Fabric: The Complex Game of Distance and Proximity in European Upper‐Middle‐Class Residential Strategies

This article presents an open discussion of the processes of urban secession and gentrification in contemporary European cities, arguing that intergroup social dynamics in urban spaces are generally more complex than either extreme mutual avoidance or the colonization of neighbourhoods by the wealthiest groups. We analyse the residential strategies of urban upper‐middle class managers in various European metropolitan areas through in‐depth semi‐structured interviews to argue that these groups develop complex strategies of proximity and distance in relation to other social groups. The development of these ‘partial exit’ strategies takes place through specific combinations of practices that allow groups to select the dimensions they are willing to share with other social groups, and those in which they prefer a more segregated social environment for themselves and their families. The responses of our interviewees were consistently more nuanced and complex than suggested by a simplistic theory about their drive to withdraw from society, forcing us to develop more sophisticated conceptual frameworks to account for the growing prevalence of multi‐layered identities and spheres of reference and solidarity, specific combinations of elective segregation and local involvement, and more active patterns of mobility combined with local embeddedness.     

Existence of equilibria in economies with externalities and non-convexities in an infinite-dimensional commodity space

We prove an equilibrium existence theorem for economies with externalities, general types of non-convexities in the production sector, and infinitely many commodities. The consumption sets, the preferences of the consumers, and the production possibilities are represented by set-valued mappings to take into account the external effects. The firms set their prices according to general pricing rules which are supposed to have bounded losses and may depend upon the actions of the other economic agents. The commodity space is L_∞(M,M,μ), the space of all μ-essentially bounded M-measurable functions on M.As for our existence result, we consider the framework of Bewley (1972). However, there are four major problems in using this technique. To overcome two of these difficulties, we impose strong lower hemi-continuity assumptions upon the economies. The remaining problems are removed when the finite economies are large enough.Our model encompasses previous works on the existence of general equilibria when there are externalities and non-convexities but the commodity space is finite dimensional and those on general equilibria in non-convex economies with infinitely many commodities when no external effect is taken into account.     

Statistical Assessment of Numerical Models*

Evaluation of physically based computer models for air quality applications is crucial to assist in control strategy selection. The high risk of getting the wrong control strategy has costly economic and social consequences. The objective comparison of modeled concentrations with observed field data is one approach to assessment of model performance. For dry deposition fluxes and concentrations of air pollutants there is a very limited supply of evaluation data sets. We develop a formal method for evaluation of the performance of numerical models, which can be implemented even when the field measurements are very sparse. This approach is applied to a current U.S. Environmental Protection Agency air quality model. In other cases, exemplified by an ozone study from the California Central Valley, the observed field is relatively data rich, and more or less standard geostatistical tools can be used to compare model to data. Yet another situation is when the cost of model runs is prohibitive, and a statistical approach to approximating the model output is needed. We describe two ways of obtaining such approximations. A common technical issue in the assessment of environmental numerical models is the need for tools to estimate nonstationary spatial covariance structures. We describe in detail two such approaches.     

In Good Company: When Small and Medium‐Sized Enterprises Acquire Multiplex Knowledge from Key Commercial Partners

This study explores the specific conditions under which key strategic alliances of small and medium‐sized enterprises (SMEs) with commercial partners can become multiplex in knowledge exchange. Using survey data from a sample of 150 Spanish SMEs in the information and communication technology (ICT) industry, we find that trust creates an appropriate context for the concurrent acquisition of technological, market, and managerial knowledge. When the SME and its key commercial partner exhibit significant strategic, technological, and market differences, however, the SME's ability to acquire different types of knowledge diminishes considerably, reducing the positive impact of trust on knowledge multiplexity.