Visual displays: analytical study and applications to graphs and real data

Principal axis methods such as principal component analysis (PCA) and correspondence analysis (CA) are useful for identifying structures in data through interesting planar graphic displays. However, some kinds of data sets can be dealt alternatively with PCA or CA. This paper focuses on methods, such as PCA and CA, and on visual displays. Our aim is to illustrate the implications for a potential user of selecting either method, and its advantages and disadvantages, from an applied point of view. This is a matter covered broadly in textbooks and elsewhere considering theoretical arguments. Our purpose is to contribute to the comparison between these methods, over the same data set, in order to illustrate them for the practitioner. In the first part of this paper we present a novel analytical study of a binary matrix associated with a non-oriented axis-symmetric graph and show that CA outperforms standardized PCA for the reconstitution and visualization of such kind of graphs. In the second part we present a case using real data dealing with the distribution of employees in different economic sectors for the countries of the European Union, analyzed by means of standardized PCA and two-way CA, in order to see the differences between the two methods in practice.     

Income based price subsidies and parallel imports

We present a policy game where a Rich country has a higher ability than a Poor country to commit to certain elements of health policy such as providing income related price subsidies and allowing parallel imports (PI). When allowing PI is not a choice for the Poor country, the Rich country allows PI and both countries provide a subsidy to their poorer buyers as the subgame perfect equilibrium policies. However, when the Poor is able to PI a different equilibrium may arise. We show that the ability of the Poor to allow PI might increase welfare in this country even if it is never implemented. We also prove that as the Poor country gets richer, it will not be in their best interest to sign an agreement with the Rich to commit to not allowing PI.     

WHY FREE MARKETS SHOULD NOT BE BLAMED FOR THE CURRENT RECESSION

Interventionist thinkers are now claiming intellectual victory, blaming the free‐market system and its ideology for the current economic collapse. We find this thesis untenable, drawing on the Austrian Business Cycle Theory. Instead, we argue that the roots of our present downturn lie in the monetary system, whose institutional structure is far from any free‐market ideal. Moreover, several government policies have contributed to the problems.     

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.     

Motivation in the teaching of Physical Education according to the Achievement Goal Theory: methodological considerations

The present study shows how the evaluation of sport motivation according to Achievement Goal Theory is different if the criteria used are predominant goal orientation or motivational profile combination, as well as presenting its relationship with other variables such as the amount of sport practise or the level of competition and success achieved. Seventy two men and women participated, all students of Physical Educational and Sport Science, completing the Questionnaire on Motivational Orientation in Sport ((Guivernau and Duda, Revista de Psicología del Deporte, 5, 1994) a Spanish adaptation of the Task and Ego Orientation in Sport Questionnaire, TEOSQ, (Duda, J Sport Exerc Psychol, 11, 1989)). The results showed the existence of different motivational relationships with variables of the practise of sport, depending on the type of profile used. Finally, the practical implications of these findings are discussed with respect to the motivational climate generated in the teaching of Physical Education.     

Codes of Best Practice in competitive markets for managers

We study the corporate governance of firms in environments where possibly heterogeneous shareholders compete for possibly heterogeneous managers. A firm, formed by a shareholder and a manager, can sign either an incentive contract or a contract including a Code of Best Practice. A Code allows for better management control, but makes it hard for managers to react quickly when market conditions change. Codes tend to be adopted in markets with low volatility and in environments where managers obtain low levels of benefits. The firms with the best projects tend to adopt a Code when managers are not too heterogeneous, while the best managers tend to be hired through incentive contracts when the projects are similar. Although the matching between shareholders and managers is often positively assortative, shareholders with the best projects might be willing to renounce hiring the best managers; instead, signing contracts including Codes with lower-ability managers.     

How Do Squatters Deal with the State? Legalization and Anomalous Institutionalization in Madrid

Radical and autonomous urban movements like the European squatters' movement tend to resist integration into the institutions of the state, although particular legal and political conditions in each country or city may significantly alter this tendency. In this article, I examine the controversial issue of ‘institutionalization’ among squatters, focusing on the few cases of legalized squats (social centres) in the city of Madrid. Negotiations with the state authorities and processes of legalization are the major forms of institutionalization involving squatters. However, an anomalous kind of institutionalization also emerges once squats, whether legalized or not, become consolidated and socially accepted. For squatting to have a successful impact, then, depends on both the type of autonomy achieved by squatters and the different outcomes of the processes of institutionalization. The case of Madrid provides empirical evidence that: (1) negotiations with state authorities were very frequent among squatters, but most were defensive; (2) the few cases of legalization were due to specific conditions such as the urban centrality of the squats, single‐issue identities, social network solidarity, favourable media coverage, formal organizations working as facilitators and the squatters' leadership of the process. Furthermore, legalized squats in Madrid preserved a high degree of autonomy, self‐management and ties to other radical social movements. In conclusion, both the legalized squats and the squatters' movement in Madrid as a whole, avoided ‘terminal institutionalization’ and, instead, gave shape to a ‘flexible’ one.     

Mergers in asymmetric Stackelberg markets

It is well known that the profitability of horizontal mergers with quantity competition is scarce. However, in an asymmetric Stackelberg market we obtain that some mergers are profitable. Our main result is that mergers among followers become profitable when the followers are inefficient enough. In this case, leaders reduce their output when followers merge and this reduction renders the merger profitable. This merger increases price and welfare is reduced.