The optimal behaviour of firms facing stochastic costs

This paper aims at assessing the optimal behavior of a firm facing stochastic costs of production. In an imperfectly competitive setting, we evaluate to what extent a firm may decide to locate part of its production in other markets different from which it is actually settled. This decision is taken in a stochastic environment. Portfolio theory is used to derive the optimal solution for the intertemporal profit maximization problem. In such a framework, splitting production between different locations may be optimal when a firm is able to charge different prices in the different local markets.

Research policy and endogenous growth

This paper studies the effects of different types of research policy on economic growth. We find that while tax incentives to private research, public funding of private projects, and basic research performed at public institutions have unambiguously positive effects on economic growth, performing applied research at public institutions could have negative growth effects. This is due to the large crowding out of private research caused by public R\&D when it competes with private firms in the "patent race". Concerning the effects of these policies on welfare, it is found that research policy can either improve or reduce consumer welfare depending on the characteristics of the policy and that an excessively high research subsidy will reduce it.

Endogenous capacity utilization and the asymmetric effects of monetary policy

This paper investigates the role of variable capacity utilization as a source of asymmetries in the relationship between monetary policy and economic activity within a dynamic stochastic general equilibrium framework. The source of the asymmetry is directly linked to the bottlenecks and stock-outs that emerge from the existence of capacity constraints in the real side of the economy. Money has real effects due to the presence of rigidities in households' portfolio decisions in the form of a Luces-Fuerst 'limited participation' constraint. The model features variable capacity utilization rates across firms due to demand uncertainty. A monopolistic competitive structure provides additional effects through optimal mark-up changes. The overall message of this paper for monetary policy is that the same actions may have different effects depending on the capacity utilization rate of the economy.

Estructura de les xarxes tròfiques i mecanisme de selecció de preses

Les xarxes tròfiques o alimentàries subministren una representació gràfica de quina espècie menja a quina altra en un ecosistema. Les xarxes tròfiques empíriques publicades són cada vegada més complexes, i es fa més patent la qüestió de si hi ha trets comuns a totes elles. En els darrers anys s’ha realitzat un gran esforç per modelitzar l’arquitectura d’aquestes xarxes. En particular, dos models han rebut especial atenció: el model de nínxol i el de jerarquies. Tots dos models reprodueixen satisfactòriament un bon nombre de propietats estadístiques globals de les xarxes empíriques més completes. Hipotèticament però, els diferents mecanismes de selecció de preses en els models de nínxol i de jerarquies haurien de generar estructures locals diferents en les xarxes. Utilitzant un mètode de subxarxes (també subgrafs o motius ) que permet l’anàlisi quantitativa, s’ha analitzat l’arquitectura local de les xarxes amb l’objectiu de poder discernir quin dels dos models és més realista.

Nuclear Weapons as Symbols. The Role of Norms in Nuclear Policy Making

Throughout history, nuclear weapons have been considered to be the ultimate weapons. This understanding largely detached them from the portfolio of conventional military means and assigned them a symbolic meaning that influenced the identity and norms creation of nations. In most countries today, the development of nuclear weapons is considered morally prohibitive, incompatible with a country’s identity and international outlook. In some states, however, these negative norms are overridden by a positive set of norms, causing nuclear weapons to become either symbols of invulnerability to perceived threats or the regalia of major power status. Main purpose of this paper is to explore on the conditions that cause most states to develop a moral aversion to nuclear weapons, yet effectively lead to their glorification in others. Many studies on the normative understanding of nuclear weapons consider the existence of a negative normative predisposition, often referred to as ‘nuclear taboo’, as a major factor in preventing their acquisition and use. Other studies acknowledge the existence of a nuclear taboo inhibiting the use of nuclear weapons, but point to the existence of the opposing effect of norms, frequently referred to as the ‘nuclear myth’, when it comes to the acquisition of nuclear weapons. This myth emerges when certain symbolic meanings are attached to nuclear weapons, such as a state’s identity, self-image, and its desired position in the international system. With 180 odd countries in the world abstaining from the acquisition of nuclear weapons and 8 countries in possession of them (with two further countries assumed to have pursued their acquisition), one might consider the dominance of the nuclear taboo over the nuclear myth to be the rule. The core question is thus why and how this relationship reversed in the case of defectors.

The biophysical perspective of a middle income economy: material flows in Mexico

We analyse natural resource use dynamics in the Mexican economy during the last three decades. Despite low and uneven economic growth, the extraction and use of materials in the Mexican economy has continuously increased during the last 30 years. In this period, population growth rather than economic growth was the main driving force for biophysical growth. In addition, fundamental changes have taken place in the primary sectors, in manufacturing, and in household consumption and these are reflected in an increasing emphasis on the use of fossil fuels and construction materials. Mexico’s economy has been strongly influenced by international trade since the country commenced competing in international markets. In the 1970s, Mexico mainly exported primary resources. This pattern has changed and manufactured goods now have a much greater importance due to a boom in assembling industries. In contrast with other Latin American countries, Mexico has achieved a diversification of production, moving towards technology-intensive products and a better mix in its export portfolio. However, crude oil exports still represent the single most important export good. Mexico’s material consumption is still well below the OECD average but is growing fast and the current resource use patterns may well present serious social and environmental problems to the medium and long term sustainability of Mexico’s economy and community. Information on natural resource use and resource productivity could provide valuable guidance for economic policy planning in Mexico.

In Search of a theory of debt management

A growing literature integrates theories of debt management into models of optimal fiscal policy. One promising theory argues that the composition of government debt should be chosen so that fluctuations in the market value of debt offset changes in expected future deficits. This complete market approach to debt management is valid even when the government only issues non-contingent bonds. A number of authors conclude from this approach that governments should issue long term debt and invest in short term assets. We argue that the conclusions of this approach are too fragile to serve as a basis for policy recommendations. This is because bonds at different maturities have highly correlated returns, causing the determination of the optimal portfolio to be ill-conditioned. To make this point concrete we examine the implications of this approach to debt management in various models, both analytically and using numerical methods calibrated to the US economy. We find the complete market approach recommends asset positions which are huge multiples of GDP. Introducing persistent shocks or capital accumulation only worsens this problem. Increasing the volatility of interest rates through habits partly reduces the size of these simulations we find no presumption that governments should issue long term debt ? policy recommendations can be easily reversed through small perturbations in the specification of shocks or small variations in the maturity of bonds issued. We further extend the literature by removing the assumption that governments every period costlessly repurchase all outstanding debt. This exacerbates the size of the required positions, worsens their volatility and in some cases produces instability in debt holdings. We conclude that it is very difficult to insulate fiscal policy from shocks by using the complete markets approach to debt management. Given the limited variability of the yield curve using maturities is a poor way to substitute for state contingent debt. The result is the positions recommended by this approach conflict with a number of features that we believe are important in making bond markets incomplete e.g allowing for transaction costs, liquidity effects, etc.. Until these features are all fully incorporated we remain in search of a theory of debt management capable of providing robust policy insights.

Patentes y alimentos

El panorama internacional sobre la protecció de les varietats vegetals, en concret el sistema de patents europeu i el de protecció d'obtencions vegetals (UPOV), la seva regulació i abast a la llum de la Jurisprudència de l'Oficina Europea de Patents (OEP) i del “Cas Bròcoli”; número de Patent Europea EP 1 069 819.

The effects of teacher talk on students’ oral productions

The present study is a brief personal enquiry into the teaching and learning of EFL in the classroom with an orientation to action and personal professional development. It focuses on teacher talk, making special emphasis on questions, as well as on students’ resulting oral productions. The research contains samples of empirical data, which include their interpretations in the light of relevant research literature, and a more personal overall reflection of the teaching practice. Both the analysis and the reflections derive to a large extent from the self-observation paper 1 (SO1) and the Practicum portfolio (PP) developed within the TED Masters Degree practicum stages

Inclusió de les TIC en el portafoli de l'estudiant per a l'ensenyament dels mètodes numèrics

La finalitat d’aquest projecte ha estat la millora de la formació global dels estudiants. Concretament, mitjançant la creació d’un portafolis que contingui les diferents activitats que ha realitzat l’estudiant al llarg del curs es pretén potenciar tant les competències específiques com les competències transversals dels estudiants. Concretament, aquest objectiu s'ha assolit mitjançant el disseny i el desenvolupament de: 1. nou material docent corresponent a la presentació dels continguts de l’assignatura (apunts, presentacions, animacions,... ) amb el que s'ha pretès promoure el treball individual i la capacitat d’autoaprenentatge dels estudiants. 2. sesions dirigits que es realitzen en aules informàtiques amb el que s'ha volgut incrementar la motivació i desenvolupar un esperit crític dels estudiants 3. treballs tutelats que els estudiants realitzaran en grups, posteriorments pesentaran a la resta de companys i que finalment condueixen a la redacció d’un informe final. D'aquesta manera s'ha pretès desenvolupar les competències transversals dels estudiants

Grup de treball en el portafoli de l'estudiant (GTPoE)

El projecte del grup de treball en el portafoli d’aprenentatge de l'estudiant de la UPC (GtPoE) ha tingut una durada d'un any i s'ha realitzat a la Universitat Politècnica de Catalunya. Els objectius del projecte, que majoritàriament s’han assolit, han estat essencialment: (1) formació d'un grup d’interès per impulsar el portafoli i portafoli electrònic com a eines d'avaluació vàlides en el context nou de l'EEES, format per professors de la UPC i d’altres universitats que s’han volgut incorporar; (2) posta a punt i ús d’una plataforma intranet i web per a la coordinació del grup i exposició de materials; (3) realització de seminaris específics amb ponents expert en aquesta matèria per assolir les bases de la metodologia; (4) assaig per part de professors del grup de treball, d’experiències del portafoli de l’estudiant en assignatures tant obligatories com optatives en diversos centres de la UPC, i la introducció del portafoli de la carrera (o carpeta de competències) en l’EPSC; (5) adquirir documentació i referències bibliogràfiques sobre aquesta eina del portafoli i altres tècniques d’innovació docent; i (6), participar en congressos i jornades per explicar els resultats del projecte. Actualment, al final d’aquest projecte, el grup té 26 membres i la voluntat de continuar desenvolupant la tasca d’inserció del portafoli en els nous plans d’estudis. Així com també es treballa coordinadament amb els altres grups d’interès que s’han format al voltant de l’ICE de la UPC a l'entorn de la innovació docent, al mateix temps que es participa en les activitats que desenvolupa la RED E-Portfolio a nivell estatal amb objectius similars coordinada per professors de la UOC.

Ampliació i extensió en l'ús del portafolis digital en l'avaluació de l'alumnat

El treball realitzat amb l’ajuda MQD2006 està relacionat amb l’ús de portafolis electrònics en un context universitari. Els objectius que ens havíem traçat, eren: 1)Dissenyar una versió beta del portafolis digital desenvolupat adhoc pel grup 2)Implementar una metodologia avaluativa basada en el portafolis digital desenvolupat 3)Generar portafolis digitals com a model de bones pràctiques d’avaluació de l’alumnat 4)Recollir dades sobre el seu funcionament en relació a l’alumnat A més dels anteriors objectius, relacionats amb els aspectes pedagògics freuit de la implementació i ús dels portafolis digitals, hi ha dos objectius relacionats amb aspectes didàctics. Aquests són: 5) Anàlisi dels canvis en la metodologia didàctica i en els continguts curriculars 6) Anàlisi de criteris de sostenibilitat de la utilització continuada del portafolis digital. Almenys 5 d’aquests 6 objectius s’han complert de manera completa, i un (el nombre cinc) ha quedat solament esbossat. Per altra banda, alguns resultats inesperats s’han produït en aquests dos anys i es poden afegir a aquesta llista inicial: 7) Expansió i difusió de l’experiència cap a altres universitats. 8) Possibilitat de plantejar un projecte d’investigació bàsica sobre les conseqüències de l’ús de portafolis en la docència universitària basada en l’EEES. La Memòria seguirà de prop aquests objectius, si bé es distribuiran d’una manera diferent. Com a resultats i conclusions hem pogut veure que l’eina ha estat ben valorada en quant a la metodologia d’ús proposada, en quant al propi seguiment de l’aprenentatge i per una autoavaluació continuada. Hem vist una millora en les reflexions dels estudiants fent servir un diàleg on-line entre professor-estudiant. D’altra banda, hem detectat que es requereix millorar la seva usabilitat, un ús continuat més llarg i algunes recomanacions encarades al treball docent del professorat i no tant de l’eina.

A logistic regression approach to estimating customer profit loss due to lapses in insurance

This article focuses on business risk management in the insurance industry. A methodology for estimating the profit loss caused by each customer in the portfolio due to policy cancellation is proposed. Using data from a European insurance company, customer behaviour over time is analyzed in order to estimate the probability of policy cancelation and the resulting potential profit loss due to cancellation. Customers may have up to two different lines of business contracts: motor insurance and other diverse insurance (such as, home contents, life or accident insurance). Implications for understanding customer cancellation behaviour as the core of business risk management are outlined.

Credit risk contributions under the Vasicek one-factor model: a fast wavelet expansion approximation

To measure the contribution of individual transactions inside the total risk of a credit portfolio is a major issue in financial institutions. VaR Contributions (VaRC) and Expected Shortfall Contributions (ESC) have become two popular ways of quantifying the risks. However, the usual Monte Carlo (MC) approach is known to be a very time consuming method for computing these risk contributions. In this paper we consider the Wavelet Approximation (WA) method for Value at Risk (VaR) computation presented in [Mas10] in order to calculate the Expected Shortfall (ES) and the risk contributions under the Vasicek one-factor model framework. We decompose the VaR and the ES as a sum of sensitivities representing the marginal impact on the total portfolio risk. Moreover, we present technical improvements in the Wavelet Approximation (WA) that considerably reduce the computational effort in the approximation while, at the same time, the accuracy increases.

How to use the standard model with own data?

In this work discuss the use of the standard model for the calculation of the solvency capital requirement (SCR) when the company aims to use the specific parameters of the model on the basis of the experience of its portfolio. In particular, this analysis focuses on the formula presented in the latest quantitative impact study (2010 CEIOPS) for non-life underwriting premium and reserve risk. One of the keys of the standard model for premium and reserves risk is the correlation matrix between lines of business. In this work we present how the correlation matrix between lines of business could be estimated from a quantitative perspective, as well as the possibility of using a credibility model for the estimation of the matrix of correlation between lines of business that merge qualitative and quantitative perspective.