Desarrollo de un programa informático de simulación de ciclos económicos.

Se trata esencialmente de resolver dos problemas básicos:Por una parte contar con apoyos fundamentales para el análisis teórico y empírico de los modelos dinámicos, con aplicaciones al caso español; y, en segundo término, disponer de una herramienta computacional para hacer frente a una de las áreas peor estudiadas del análisis económico. Se generan y resuelven cuatro modelos para revisar y evaluar computacionalmente cuatro áreas que combinan la ausencia y/o presencia de sector público, junto con las alternativas de trabajo divisible y nodivisible. Los programas informáticos permiten resolver y simular los modelos del ciclo comentados, y presentan para cada caso una vertiente específica escrita en Matemática y otra genérica escrita en lenguaje Gauss común para todos los modelos. Este programa proporciona una primera descripción estadística de los resultados, que resulta útil para determinar a grandes rasgos el ajuste de la simulación de los datos reales. Rodado el programa se pueden hacer aparecer en pantalla las series de desviaciones de las macrovariables fundamentales: el PIB, los consumos privado y público, el empleo, la acumulación de capital, etc. El objetivo esencial de esta estructura de apoyo a la práctica docente se satisface con gran facilidad de manejo. Por otra parte, estimula el manejo y la introducción de datos relativos a la estructura de la economía, la incorporación, el análisis deratios productivos y de mercado, la familiarización con coeficientes de correlación de los shocks tecnológicos, y la calibración del conjunto de elementos incorporados, como propuestas de comportamiento económico a corroborar. Es un programa nuevo, completo y asequible para mejorar la docencia en el área..

The creation of euro area financial safety nets. Bruegel Working Paper 2012/09, July 2012

The financial crisis has exposed the need to devise stronger and broader international and regional safety nets in order to deal with economic and financial shocks and allow for countries to adjust. The euro area has developed several such mechanisms over the last couple of years through a process of trial and error and gradual enhancement and expansion. Their overall architecture remains imperfect and leaves areas of vulnerabilities. This paper provides an overview of the recent financial stability mechanisms and their various shortcomings and tries to brush the outline of a more comprehensive safety net architecture that would coherently address the banking, sovereign and external imbalances crises against both transitory and more permanent shocks. It aims to provide a roadmap for further improvements of the current mechanism and the creation of new devices including a banking resolution mechanism and amore powerfulmechanismto provide financial assistance addressing both the sovereign and external dimensions of the shocks thereby reducing the need for the ECB to fill the current void.

A budget for Europe's Monetary Union. Bruegel Policy Contribution 2012/22, December 2012

In a monetary union, national fiscal deficits are of limited help to counteract deep recessions; union-wide support is needed. A common euro-area budget (1) should provide a temporary but significant transfer of resources in case of large regional shocks, (2) would be an instrument to counteract severe recessions in the area as a whole, and (3) would ensure financial stability. The four main options for stabilisation of regional shocks to the euro area are: unemployment insurance, payments related to deviations of output from potential, the narrowing of large spreads, and discretionary spending. The common resource would need to be well-designed to be distributionally neutral, avoid free-riding behaviour and foster structural change while be of sufficient size to have an impact. Linking budget support to large deviations of output from potential appears to be the best option. A borrowing capacity equipped with a structural balanced budget rule could address area-wide shocks. It could serve as the fiscal backstop to the bank resolution authority. Resources amounting to 2 percent of euro-area GDP would be needed for stabilisation policy and financial stability.

The false promise of a eurozone budget. CEPS Commentary, 7 December 2012

n this new CEPS commentary, CEPS Director Daniel Gros takes a closer look at the US experience to point out that the federal budget provides much less insurance against state specific shocks than widely assumed, while the US Banking Union act as a very powerful shock absorber. Accordingly, he argues that the euro’s long-term stability depends far more on completing plans for a European banking union than on the introduction of a fiscal capacity for the eurozone.

Options for a Euro-area fiscal capacity. Bruegel Policy Brief 2013/01, January 2013

Europe has responded to the crisis with strengthened budgetary and macroeconomic surveillance, the creation of the European Stability Mechanism, liquidity provisioning by resilient economies and the European Central Bank and a process towards a banking union. However, a monetary union requires some form of budget for fiscal stabilisation in case of shocks, and as a backstop to the banking union. This paper compares four quantitatively different schemes of fiscal stabilisation and proposes a new scheme based on GDP-indexed bonds. The options considered are: (i) A federal budget with unemployment and corporate taxes shifted to euro-area level; (ii) a support scheme based on deviations from potential output;(iii) an insurance scheme via which governments would issue bonds indexed to GDP, and (iv) a scheme in which access to jointly guaranteed borrowing is combined with gradual withdrawal of fiscal sovereignty. Our comparison is based on strong assumptions. We carry out a preliminary, limited simulation of how the debt-to-GDP ratio would have developed between 2008-14 under the four schemes for Greece, Ireland, Portugal, Spain and an ‘average’ country.The schemes have varying implications in each case for debt sustainability

Benchmarking 2D hydraulic models for urban flooding

This paper describes benchmark testing of six two-dimensional (2D) hydraulic models (DIVAST, DIVASTTVD, TUFLOW, JFLOW, TRENT and LISFLOOD-FP) in terms of their ability to simulate surface flows in a densely urbanised area. The models are applied to a 1·0 km × 0·4 km urban catchment within the city of Glasgow, Scotland, UK, and are used to simulate a flood event that occurred at this site on 30 July 2002. An identical numerical grid describing the underlying topography is constructed for each model, using a combination of airborne laser altimetry (LiDAR) fused with digital map data, and used to run a benchmark simulation. Two numerical experiments were then conducted to test the response of each model to topographic error and uncertainty over friction parameterisation. While all the models tested produce plausible results, subtle differences between particular groups of codes give considerable insight into both the practice and science of urban hydraulic modelling. In particular, the results show that the terrain data available from modern LiDAR systems are sufficiently accurate and resolved for simulating urban flows, but such data need to be fused with digital map data of building topology and land use to gain maximum benefit from the information contained therein. When such terrain data are available, uncertainty in friction parameters becomes a more dominant factor than topographic error for typical problems. The simulations also show that flows in urban environments are characterised by numerous transitions to supercritical flow and numerical shocks. However, the effects of these are localised and they do not appear to affect overall wave propagation. In contrast, inertia terms are shown to be important in this particular case, but the specific characteristics of the test site may mean that this does not hold more generally.

Cone model-based SEP event calculations for applications to multipoint observations

The problem of modeling solar energetic particle (SEP) events is important to both space weather research and forecasting, and yet it has seen relatively little progress. Most important SEP events are associated with coronal mass ejections (CMEs) that drive coronal and interplanetary shocks. These shocks can continuously produce accelerated particles from the ambient medium to well beyond 1 AU. This paper describes an effort to model real SEP events using a Center for Integrated Space weather Modeling (CISM) MHD solar wind simulation including a cone model of CMEs to initiate the related shocks. In addition to providing observation-inspired shock geometry and characteristics, this MHD simulation describes the time-dependent observer field line connections to the shock source. As a first approximation, we assume a shock jump-parameterized source strength and spectrum, and that scatter-free transport occurs outside of the shock source, thus emphasizing the role the shock evolution plays in determining the modeled SEP event profile. Three halo CME events on May 12, 1997, November 4, 1997 and December 13, 2006 are used to test the modeling approach. While challenges arise in the identification and characterization of the shocks in the MHD model results, this approach illustrates the importance to SEP event modeling of globally simulating the underlying heliospheric event. The results also suggest the potential utility of such a model for forcasting and for interpretation of separated multipoint measurements such as those expected from the STEREO mission.

Bayes estimates of distance-to-market: Transactions costs, cooperatives and milk-market development in the Ethiopian highlands

Rationalizing non-participation as a resource deficiency in the household, this paper identifies strategies for milk-market development in the Ethiopian highlands. The additional amounts of covariates required for Positive marketable surplus -'distances-to market'-are computed from a model in which production and sales are correlated; sales are left-censored at some Unobserved thresholds production efficiencies are heterogeneous: and the data are in the form of a panel. Incorporating these features into the modeling exercise ant because they are fundamental to the data-generating environment. There are four reasons. First, because production and sales decisions are enacted within the same household, both decisions are affected by the same exogenous shocks, and production and sales are therefore likely to be correlated. Second. because selling, involves time and time is arguably the most important resource available to a subsistence household, the minimum Sales amount is not zero but, rather, some unobserved threshold that lies beyond zero. Third. the Potential existence of heterogeneous abilities in management, ones that lie latent from the econometrician's perspective, suggest that production efficiencies should be permitted to vary across households. Fourth, we observe a single set of households during multiple visits in a single production year. The results convey clearly that institutional and production) innovations alone are insufficient to encourage participation. Market-precipitating innovation requires complementary inputs, especially improvements in human capital and reductions in risk. Copyright (c) 20 08 John Wiley & Sons, Ltd.

Effective livelihood adaptation to climate change disturbance: scale dimensions of practice in Mozambique

Natural resource-dependent societies in developing countries are facing increased pressures linked to global climate change. While social-ecological systems evolve to accommodate variability, there is growing evidence that changes in drought, storm and flood extremes are increasing exposure of currently vulnerable populations. In many countries in Africa, these pressures are compounded by disruption to institutions and variability in livelihoods and income. The interactions of both rapid and slow onset livelihood disturbance contribute to enduring poverty and slow processes of rural livelihood renewal across a complex landscape. We explore cross-scale dynamics in coping and adaptation response, drawing on qualitative data from a case study in Mozambique. The research characterises the engagements across multiple institutional scales and the types of agents involved, providing insight into emergent conditions for adaptation to climate change in rural economies, The analysis explores local responses to climate shocks, food security and poverty reduction, through informal institutions, forms of livelihood diversification and collective land-use systems that allow reciprocity, flexibility and the ability to buffer shocks. However, the analysis shows that agricultural initiatives have helped to facilitate effective livelihood renewal, through the reorganisation of social institutions and opportunities for communication, innovation and micro-credit. Although there are challenges to mainstreaming adaptation at different scales, this research shows why it is critical to assess how policies can protect conditions for emergence of livelihood transformation. (C) 2008 Elsevier Ltd. All rights reserved.

Shock persistence in a dual economy model of India

This article examines shock persistence in agricultural and industrial output in India. Drawing on the dual economy literature, the linkages between the sectors through the terms of trade are emphasised. However different dual economy models make differing assumptions regarding the categorisation of variables as being either endogenous or exogenous and this distinction is crucial in explaining the pattern of shock persistence. Using annual data for 1955-95, our results show that shocks to both output series are permanent while those to the terms of trade are transient.

Real gas flows in a duct

A numerical scheme is presented for the solution of the Euler equations of compressible flow of a real gas in a single spatial coordinate. This include flow in a duct of variable cross-section as well as flow with cylindrical or spherical symmetry, and can prove useful when testing codes for the two-dimensional equations governing compressible flow of a real gas. The scheme is applied with success to a problem involving the interaction of converging and diverging cylindrical shocks for four equations of state and to a problem involving the reflection of a converging shock.

Cylindrically symmetric flows in a Lagrangian frame

An approximate Riemann solver, in a Lagrangian frame of reference, is presented for the compressible flow equations with cylindrical and spherical symmetry, including flow in a duct of variable cross section. The scheme is applied to a cylindrically symmetric problem involving the interaction of shocks.

High hydrostatic pressure resistance of Campylobacter jejuni after different sublethal stresses

Aims: To study the development of resistance responses in Campylobacter jejuni to High Hydrostatic Pressure (HHP) treatments after the exposure to different stressful conditions that may be encountered in food processing environments, such as acid pH, elevated temperatures and cold storage. Methods and Results: C. jejuni cells in exponential and stationary growth phase were exposed to different sublethal stresses (acid, heat and cold shocks) prior to evaluate the development of resistance responses to HHP. For exponential-phase cells, neither of the conditions tested increased nor decreased HHP resistance of C. jejuni. For stationary-phase cells, acid and heat adaptation sensitized C. jejuni cells to the subsequent pressure treatment. On the contrary, cold-adapted stationary-phase cells developed resistance to HHP. Conclusions: Whereas C. jejuni can be classified as a stress sensitive microorganism, our findings have demonstrated that it can develop resistance responses under different stressing conditions. The resistance of stationary phase C. jejuni to HHP was increased after cells were exposed to cold temperatures. Significance and Impact of the Study: The results of this study contribute to a better knowledge of the physiology of C. jejuni and its survival to food preservation agents. Results here presented may help in the design of combined processes for food preservation based on HHP technology.

Flexible rules cum constrained discretion: a new consensus in monetary policy

This paper demonstrates that recent influential contributions to monetary policy imply an emerging consensus whereby neither rigid rules nor complete discretion are found optimal. Instead, middle-ground monetary regimes based on rules (operative under 'normal' circumstances) to anchor inflation expectations over the long run, but designed with enough flexibility to mitigate the short-run effect of shocks (with communicated discretion in 'exceptional' circumstances temporarily overriding these rules), are gaining support in theoretical models and policy formulation and implementation. The opposition of 'rules versus discretion' has, thus, reappeared as the synthesis of 'rules cum discretion', in essence as inflation-forecast targeting. But such synthesis is not without major theoretical problems, as we argue in this contribution. Furthermore, the very recent real-world events have made it obvious that the inflation targeting strategy of monetary policy, which rests upon the new consensus paradigm in modern macroeconomics is at best a 'fair weather' model. In the turbulent economic climate of highly unstable inflation, deep financial crisis and world-wide, abrupt economic slowdown nowadays this approach needs serious rethinking to say the least, if not abandoning it altogether

Asymmetric adjustment in the City of London office market

Earlier estimates of the City of London office market are extended by considering a longer time series of data, covering two cycles, and by explicitly modeling of asymmetric space market responses to employment and supply shocks. A long run structural model linking real rental levels, office-based employment and the supply of office space is estimated and then rental adjustment processes are modeled using an error correction model framework. Rental adjustment is seen to be asymmetric, depending both on the direction of the supply and demand shocks and on the state of the space market at the time of the shock. Vacancy adjustment does not display asymmetries. There is also a supply adjustment equation. Two three-equation systems, one with symmetric rental adjustment and the other with asymmetric adjustment, are subjected to positive and negative shocks to employment. These illustrate differences in the two systems.