Size,time-varying beta,and conditional heteroscedasticity in UK stock returns

The purpose of this study is to examine the relationship between firm size and time-varying betas of UK stocks. We extend the Schwert and Seguin (1990)(Journal of Finance 45, 1120–1155) methodology by explicitly modeling conditional heteroscedasticity in the market model residual returns. Our results show that the time-varying coefficient is not statistically significant for both small and large firm stock indexes. We also find that accounting for GARCH effects in the Schwert-Seguin market model yields beta estimates that are markedly differently from those when conditional heteroscedasticity is ignored. Event studies that ignore conditional heteroscedasticity may bias the abnormal returns of small and large firms, thereby leading to a different conclusion regarding the significance of an information event.     

What is the objective of professional licensing? Evidence from the US market for lawyers

According to public interest theory, professional licensing solves the lemon problem generated by asymmetric information. In contrast, the capture theory claims that licensing aims at increasing professional salaries by restricting supply. This paper shows that the two theories can be identified using data from one regulated profession and provides an empirical application to the US market for entry level lawyers. The empirical results support capture theory.     

A learning methodology using Matlab/Simulink for undergraduate electrical engineering courses attending to learner satisfaction outcomes

Learner-centred approaches follow the prevailing tendency in modern University reforms which are primarily concerned about “how people learn”. The methodologies can be learner-centred in the sense of placing the student as the main actor of the teaching–learning process by increasing his interactivity and participation, but also considering what is relevant for the student by measuring the learner satisfaction. In order to promote both aspects, this paper proposes a synchronous software-based active methodology that makes use of the simulations to show a virtual scenario to the students and challenge them to predict and discuss the evolution of the scenario. The proposed methodology improves the visual interface, promotes discussion both among students and with the teacher in a brainstorming stage and shows real-world examples. This software-based methodology has been implemented into an Electric Machinery course at the University of Seville (Spain), and the evaluation has been carried out considering both the affective and cognitive domains. Principal components analysis proves to be useful to highlight the dimensions with a higher influence on learner satisfaction and the affective and cognitive results confirm the successful implementation of the proposal.     

On Non-Nash Equilibria

I consider generalisations of the Nash equilibrium concept based on the idea that in equilibrium the players' beliefs should not be contradicted, even if they could possibly be incorrect. This possibility depends on the information about opponents' behaviour available to the players in equilibrium. Therefore the players' information is crucial for this notion of equilibrium, called Conjectural Equilibrium in general and Rationalizable Conjectural Equilibrium (Rubinstein-Wolinsky 1994) when the game and the players' Bayesian rationality are common knowledge. In this paper I argue for a refinement of Rationalizable Conjectural Equilibrium showing by propositions and by examples how this equilibrium notion works and how the suitable equilibrium concept depends on the players' information.Journal of Economic LiteratureClassification Numbers: C72, D83, D82.     

Equilibrium with Default and Endogenous Collateral

We study a two‐period general equilibrium model with incomplete asset markets and default. We make collateral endogenous by allowing each seller of assets to fix the level of collateral. Sellers are required to provide collateral whose first‐period value, per unit of asset, exceeds the asset price by an arbitrarily small amount. Moreover, borrowers are also required to be fully covered by the purchase, in the first period, of state‐by‐state default insurance. These insurance contracts are offered by lenders. The insurance cost or revenue is a linear charge and plays the role of a spread penalizing borrowers who will incur in default and benefiting lenders who will suffer default. Under these assumptions, equilibrium always exists.     

Deposit guarantee evaluation and incentives analysis in a mutual guarantee system

This paper analyzes how the deposit guarantee value affects the risk incentives in a mutual guarantee system. We liken the guarantee’s value to that of a European-style contingent claims portfolio. The main feature emerging from our model is that a mutual guarantee system would give banks an adverse incentive to increase riskiness. To mitigate this incentive, we introduce a regulatory provision modelled using a path-dependent contingent claim. By comparing the mutual guarantee system with a non-mutual one, we show that the former is less expensive, but implies higher adverse incentives for the banks, especially for undercapitalized institutions.     

The environmental benefits of changing logistics structures for fresh vegetables

The transport phase is one of the crucial stages that can be improved to reduce the environmental impact of the fresh fruit and vegetable supply chain. In this paper, we calculate the environmental impact of feasible logistic alternatives for the above-mentioned supply chain so as to identify the type of transportation that incurs the lowest environmental costs. Specifically, we consider the early potato supply chain as a case study, as it involves one of the main fresh vegetables exported from Italy. Consumers' willingness to pay for the environmental impact of different logistic chains was obtained through life cycle assessment. Our results show that rail transport could reduce environmental impact in terms of tons of oil equivalent, environmental loads, and fuel consumption while ensuring reasonable shipment times. Development of an efficient rail transport system would be positively considered by consumers, enhancing their preferences for Italian products.