American options and callable bonds under stochastic interest rates and endogenous bankruptcy

A new characterization of the American-style option is proposed under a very general multifactor Markovian and diffusion framework. The efficiency of the proposed pricing solutions is shown to depend only on the use of a viable valuation method for the corresponding European-style option and for the transition density of the model’s state variables. Under a Gauss-Markov stochastic interest rates setup, these new American option pricing solutions are shown to offer a much better accuracy-efficiency trade-off than the approximations already available in the literature. This result is also used to price callable corporate bonds under an endogenous bankruptcy structural approach, by decomposing the option to call or default into a European put on the firm value plus two early exercise premium components.     

Waiting Lists and Patient Selection

We develop a positive model of waiting lists for public hospitals when physicians are able to divert patients from the public to the private sector. Public treatment is free but rationed, i.e., only cases meeting some medical criteria are admitted. Private treatment has no waiting time but entails payment of a fee. Physicians and patients take into account that each patient treated in the private practice reduces the waiting list for public treatment. We show that physicians do not necessarily end up treating the mildest cases from the waiting list. Our analysis is valid for a wide class of doctors' utility functions.     

Estimation in the first-order moving average model through the finite autoregressive approximation: Some asymptotic results

To estimate α in the model y_t = u_t+αu_t?1, we consider a proposal by Durbin (Biometrika, 1969). It consists in fitting an autoregression of order k to the data, and deriving from there an estimate α^. The probability limit and the variance of the limiting normal distribution of α^ are presented and discussed in detail, when the sample size T → ∞, but k remains fixed. The differences between the resulting values and those corresponding to the maximum likelihood estimator are exponentially decreasing functions of k. Several modifications of the estimator are discussed and found consistent, but asymptotically inefficient.     

Migration and the urban labour market: The case of San Salvador

This article analyzes the employment and incomes of migrants in the city of San Salvador. The study finds that, both rural-urban and urban-urban migrants experience income gains and are increasingly employed in the formal sector. However, the upward mobility of urban-urban migrants is much larger. Compared with urban natives, these migrants have higher income levels and employment rates after five years of urban residence, while rural-urban migrants earn much less and tend to remain in the informal sector more frequently. This evidence is contrary to findings obtained in other studies, for example Brazil, which showed that urban natives and migrants have comparable levels of income and employment. The authors suggest that the experience of rural-urban migrants is a result of the functioning of the urban labour market. Within this market a mechanism exists whereby access to the high-wage sector is limited by discriminating among workers. As a result, rural-urban migrants, often recognizable by their racial characteristics, are denied access to high-wage jobs.     

Minimum wages in Spain

In Spain the minimum wage appears to have no significant employment-reducing effect for workers over 18. For the under 18s, however, minimum wages and employment are negatively related. The government should consider lowering the minimum wage for younger workers.     

How does working capital management affect the profitability of Spanish SMEs?

This paper analyzes the relation between working capital management and profitability for small and medium-sized enterprises (SMEs) by controlling for unobservable heterogeneity and possible endogeneity. Unlike previous studies, we examine a non-linear relation between these two variables. Our results show that there is a non-monotonic (concave) relationship between working capital level and firm profitability, which indicates that SMEs have an optimal working capital level that maximizes their profitability. In addition, a robustness check of our results confirms that firms?? profitability decreases as they move away from their optimal level.     

Foreign aid preferences and perceptions in donor countries

We present original survey data on preferences for foreign aid in 24 donor countries from 2005 to 2008. On publicly-funded foreign aid (Official Development Assistance, or ODA), we find patterns that are consistent with a standard model of democratic policy formation, in which donations are treated as a pure public good. Controlling for perceptions of current ODA, we show that individual preferences for ODA are (i) negatively correlated with relative income within a country-year; and (ii) positively correlated with inequality at the country level. We extend the analysis to explain variation in the gap between desired aid and actual ODA, arguing that lobbying by high-income special interest groups can divert resources away from the median voter’s preferred level of aid. Consistent with this, we observe that ODA is significantly lower where policymakers are more susceptible to lobbying. Finally, we present a novel test of competing “crowding out” hypotheses. Self-reported private aid donations are negatively correlated with actual ODA, and positively correlated with perceived ODA. This finding is consistent with an emerging argument in the literature, whereby ODA crowds out private aid by enabling charities to forego fundraising activities and crowds in private aid through a signaling channel.     

An Investigation into Restaurant Attributes: A Basis for a Typology

This article has the aim of presenting the basis for a new, clearer classification of restaurant attributes. The research followed an interpretive approach with a systematic review of the literature, compared and contrasted with the findings of six focus group interviews. A new model was devised with seven categories of restaurant attributes. This article presents a model that needs to be tested. Also, follow-up articles with more detail about the attributes under each category will be presented. This article organizes the disparate literature on restaurant attributes and looks into the relationship between attributes, particularly its influence on perceived consumer value.