Spanish Stock Returns: Where is the Weather Effect?

Psychological studies support the existence of an influence of weather on mood. Saunders (1993) and Hirshleifer and Shumway (2001) argue that the weather could affect the behaviour of market traders and, therefore, it should be reflected in the stock returns. This paper investigates the possible relation between weather and market index returns in the context of the Spanish market. In 1989, this market changed its open outcry trading system into a computerised and decentralised trading system. Therefore, it is possible to check the influence of weather variables (sunshine hours and humidity levels) on index returns in an open outcry trading system, and to compare it with a screen traded environment. The empirical evidence indicates that, independently of the trading system, there is no influence of weather on stock prices. Thus, these findings do not contest the notion of efficient markets.     

A vision for Nicaragua : Health services in the new century

Nicaragua is facing a crisis in health and health care, and a health futures programme has been initiated to focus concern and mobilize key actors. Two national scenario workshops have been held at which participants constructed several scenarios describing alternative health futures for the country, with particular emphasis on the organization of health services. One or these, a scenario of profound change, was selected by the participants as their vision of the preferred future. It involves more emphasis on health promotion, decentralization of health-care services, broader participation in health matters, improved training for health professionals, and a stronger role for universities and other educational and research centres. Implications of the selected scenario regarding health policies and actions have been identified, among them being the adoption and implementation of the Ottawa Charter on Health Promotion, the organization of local health service networks, and the more active involvement of health professionals in the designing of health systems.     

R&D Project Selection Strategy: an empirical study in Spain

The author has investigated the role played by project selection methods in defining a firm's technology strategy, as exemplified by a sample of innovative companies in Spain. The information was collected by a combination of questionnaire and interview with key personnel.
The author was able to classify strategies into four groups: (1) a planning strategy, essentially a negotiation comprising top-down and bottom-up elements; (2) an economic strategy in which a large number of economic criteria set in advance by top management are used to evaluate projects; (3) a market strategy in which R&D is seen more or less as an adjunct to the Marketing function, which defines the products needed and negotiates the programme with top management; (4) a technical strategy, used in circumstances in which technological innovation is essential and in which, therefore, economic factors take a subsidiary place.
The author's data show that in companies operating a planning strategy project selection methods of various, perhaps ad hoc kinds play a key role in reaching a company consensus. For those using an economic strategy the selection criteria are predetermined and selection methods inflexible. In the case of the market strategy, evaluation methods are used solely to help to rank projects prior to selection. Firms employing the technical strategy clearly base their decisions purely on the technical merit of the various projects put up for implementation.
The paper includes information on the types of selection method used, broken down by company size and other similar criteria, and comparisons with practice in the USA, France and some other countries.     

Investment option under CIR interest rates

We analyze extensively the characteristics of the solution to an irreversible investment decision when the only source of uncertainty comes from interest rates. They are assumed to be driven by the popular Cox–Ingersoll–Ross (CIR) stochastic process. Particular attention is paid to the impact that both CIR parameters and risk aversion have on the threshold rate.     

Measuring Productive Efficiency in Input–Output Models by Means of Data Envelopment Analysis

The goal of the present research is to evaluate productive efficiency in an input–output framework by means of data envelopment analysis (DEA). This mathematical programming technique allows researchers to assess potential efficiency improvements in the form of input requirements reduction. By constructing envelopment unitary isoquants corresponding to comparable sectors across different local, regional or national economies, e.g. agriculture and manufacturing, DEA identifies as productive benchmarks those economies that exhibit the lowest technical coefficients, i.e. lowest input amount to produce one unit of output. Once these reference frontiers have been defined, it is possible to assess what would be the potential efficiency improvements available to the inefficient economies if they were to produce according to the best practice technologies of their benchmark peers. From an equivalent perspective, these simulations identify the necessary changes that each productive sector needs to undertake in order to reach the efficiency levels of the most successful economies. Finally, within Leontief’s analytical construction, these calculations allow us to assess what would have been the economy‐wid,e benefits for the inefficient economies—in terms of intermediate consumption reductions and final demand increases—of producing with best practice technologies. The model is empirically illustrated using the input–output tables for a set of OECD countries.     

Community connectivity and heterogeneity: clues and insights on cooperation on social networks

While studies on the emergence of cooperation on structured populations abound, only few of them have considered real social networks as the substrate on which individuals interact. As has been shown recently [Lozano et al., PLoS ONE 3(4):e1892, 2008], understanding cooperative behavior on social networks requires knowledge not only of their global (macroscopic) characteristic, but also a deep insight on their community (mesoscopic) structure. In this paper, we look at this problem from the viewpoint of the resilience of cooperation, in particular when there are directed exogenous attacks (insertion of pure defectors) at key locations in the network. We present results of agent-based simulations showing strong evidence that the resilience of social networks is crucially dependent on their community structure, ranging from no resilience to robust cooperative behavior. Our results have important implications for the understanding of how organizations work and can be used as a guide for organization design. This work was supported by Ministerio de Educación y Ciencia (Spain) under grants FIS2006-13321-2 and MOSAICO and by Comunidad de Madrid (Spain) under grant. SIMUMAT-CM. S. Lozano was supported by URV through a FPU grant and by the EU Integrated Project IRRIIS (027568).     

The use of Zostavax in Spain: the economic case for vaccination of individuals aged 50 years and older

Background Population aging brings up a number of health issues, one of which is an increased incidence of herpes zoster (HZ) and its complication, post-herpetic neuralgia (PHN). Zostavax vaccine has recently become available to prevent HZ and PHN. This study evaluates the cost-effectiveness of vaccination against HZ in Spain considering a vaccination of the population aged 50 years and older and comparing this to the current situation where no vaccination is being administered.

Methods An existing, validated, and published economic model was adapted to Spain using relevant local input parameters and costs from 2013.

Results Vaccinating 30% of the Spanish population aged 50 years and older resulted in €16,577/QALY gained, €2025/HZ case avoided, and €5594/PHN case avoided under the third-party payer perspective. From a societal perspective, the ICERs increased by 6%, due to the higher price of the vaccine. The number needed to vaccinate to prevent one case was 20 for HZ, and 63 for PHN3. Sensitivity analyses showed that the model was most sensitive to the HZ and PHN epidemiological data, the health state utilities values, and vaccine price used.

Conclusion Considering an acceptable range of cost-effectiveness of €30,000–€50,000 per QALY gained, vaccination of the 50+ population in Spain against HZ with a new vaccine, Zostavax, is cost-effective and makes good use of the valuable healthcare budget.     

阿根廷与中国:过去、现在与未来经济合作纵论

<正>首先,我们将关注阿根廷与中国两国的贸易关系。第一部分是关于1991年阿根廷经济模式的重要变化和2007年第三、四代共产党领导人完成的"改革开放政策"。在这一部分,我们将关注1991年～2007年的经济关系。我们将这段时期分成2个阶段:从1991年～2001年;2002年～2007年。     

Modelling conditional heteroskedasticity: Application to the “IBEX-35” stock-return index

This paper compares alternative time-varying volatility models for daily stock-returns using data from Spanish equity index IBEX-35. Specifically, we estimate a parametric family of models of generalized autoregressive heteroskedasticity (which nests the most popular symmetric and asymmetric GARCH models), a semiparametric GARCH model, the generalized quadratic ARCH model, the stochastic volatility model, the Poisson Jump Diffusion model and, finally, a nonparametric model. Those models which use conditional standard deviation (specifically, TGARCH and AGARCH models) produce better fits than all other GARCH models. We also compare the within sample predictive power of all models using a standard efficiency test. Our results show that the asymmetric behaviour of responses is a statistically significant characteristic of these data. Moreover, we observe that specifications with a distribution which allows for fatter tails than a normal distribution do not necessarily outperform specifications with a normal distribution.     

A simulation-based algorithm for American executive stock option valuation

We present an algorithm that merges a certainty-equivalence framework with the least-squares Monte Carlo algorithm to obtain the executive stock option (ESO) value for a risk-averse and undiversified agent. We account for the difference between executive’s value and firm cost of the ESO. We show how early-exercise decisions depend on executive’s preferences and its diversification degree. Because of the algorithm flexibility, it allows for multiple state-variables. As an example, we consider the case of indexed ESOs revealing a significant improvement in terms of executive’s discount respect to fixed strike ESOs.