Breaks, trends and the attribution of climate change: a time-series analysis

Climate change detection and attribution have been the subject of intense research and debate over at least four decades. However, direct attribution of climate change to anthropogenic activities using observed climate and forcing variables through statistical methods has remained elusive, partly caused by difficulties to correctly identify the time-series properties of these variables and by the limited availability of methods to relate nonstationary variables. This paper provides strong evidence concerning the direct attribution of observed climate change to anthropogenic greenhouse gases emissions by first investigating the univariate time-series properties of observed global and hemispheric temperatures and forcing variables and then by proposing statistically adequate multivariate models. The results show that there is a clear anthropogenic fingerprint on both global and hemispheric temperatures. The signal of the well-mixed Greenhouse Gases (GHG) forcing in all temperature series is very clear and accounts for most of their secular movements since the beginning of observations. Both temperature and forcing variables are characterized by piecewise linear trends with abrupt changes in their slopes estimated to occur at different dates. Nevertheless, their long-term movements are so closely related that the observed temperature and forcing trends cancel out. The warming experimented during the last century was mainly due to the increase in GHG which was partially offset by the effect of tropospheric aerosols. Other forcing sources, such as solar, are shown to only contribute to (shorter-term) variations around the GHG forcing trend.Published versio

Economia Civile

The present booklet puts together a few short contributions on the recent work by Stefano Zamagni and Luigino Bruni on the notion of civil economy. Among recent works by historians (perhaps the best known is Robert Putnam’s work on the Italian civic tradition), economists and social scientists, the book here discussed deserves a special place for delving into the history of economic thought as a method of finding new ways and establishing new paradigms in economic theorizing. After an introductory exposé by the editor, the booklet hosts a comment by Gloria Vivenza (University of Verona) which traces some the Classical roots of the notion of civil economy. Thomas Hobbes notoriously changed the phrase homo homini deus, which is sometimes quoted from Caecilius Statius, into homo homini lupus. The latter also, indeed, comes from Roman playwriters and is commonly attributed to Plautus. Today we have to go back to Statius’s sentence if we aim at an understanding of reciprocity, which is the core concept of this book. Gloria Vivenza, as a scholar on the Greek and Roman background of Political Economy, is an excellent guide in the field. The subsequent comment by Roberto Scazzieri (University of Bologna, now visiting at the University of Cambridge) puts the notion of civil economy in context with some of main strands of economic thought in the 18th century. In particular Scazzieri’s contribution highlights similarities and differences between the Italian civic tradition and the Scottish paradigm. Finally a young scholar from the Bocconi University, Francesco Boldizzoni, adds his remarks on the formative stages of the civic humanist paradigm in Italy and on the proliferation of the paradigm in Europe and, more particularly, in Britain. This booklet is closed by ‘conclusions’ by the authors of the book. The comments given here were first presented at the 8th annual Conference of ESHET, the European Society of the History of Economic Thought, held in Treviso 27-29 February 2004. A special session of the Treviso Conference was organized by the editor the present booklet on the concept of Economia civile. Thanks are due to the authors of the various comments for readily making their texts available for reproduction in this booklet. An obligation must be recorded also to dr. Elisa Portale, who has been helpful in the editing of this booklet.

Elasticity of Substitution in the U.S. Market with Endogenous Transport Costs: a Sectoral Approach

Following Anderson and Wincoop (2004) we estimate the elasticityof substitution of the goods imported by the U.S. market for the period comprehended between 1990 - 2003. Our estimates take advantage of the data ontransport costs available at six digit commodity level of the U.S. import datapublished by the U.S. Census Bureau.We obtain two different estimates of the elasticity of substitution; one atthe average aggregate level and a second one at the sectoral level. As expected, the estimates that take into account the endogeneity of transport costs are statistically different in one unit from the results obtained when we ignore the structure of transport costs. This difference is even higher when we compare the results obtained using the sectoral classification at the two digit level of the ISIC revision 2 classification.** En este artículo se presentan estimaciones de la elasticidad de sustitución de bienes importados al mercado de los EEUU en el periodo 1990{2003, siguiendo a Anderson y Wincoop (2004). Estas estimaciones aprovechan la disponibilidad de la información sobre costos de transporte de bienes publicada por la Oficina del Censo de los Estados Unidos, desagregándola a seis dígitos.Se obtienen dos estimaciones diferentes de la elasticidad de sustitución: unaa nivel agregado promedio y otra a nivel sectorial. Como puede esperarse, lasestimaciones que tienen en cuenta la endogeneidad de los costos de transporteson estadísticamente diferentes en un punto porcentual a los resultados obtenidos cuando no se contempla la estructura de los costos de transporte. Esta diferencia es incluso superior cuando comparamos los resultados obtenidos utilizando la clasificación sectorial a nivel de dos dígitos de la clasificación ISIC revisión 2.Elasticity of substitution, Transport Costs, ISIC Classification. ** Elasticidad de Sustitución, Costos de Transporte, Clasificación ISIC.

Piecemeal Oligopoly, Exchange Rate Uncertainty, and Trade Policy

RESUMEN:Este artículo analiza el efecto sistemático de la volatilidad de la tasa de cambio, cuando un gobierno local debe evaluar políticas comerciales estratégicas lineales y cuadráticas. Este ejercicio se realiza para modelosde mercado Cournot y Bertran. El modelo prueba que tanto el esquema lineal como el cuadrático tienen el mismo efecto sobre el bienestar social de los paises, y que la volatilidad de la tasa de cambio doméstica lleva a los gobiernos a reducir los subsidios a las exportaciones o bajan los impuestos a las exportaciones, de acuerdo a la variable estratégica elegida por las firmas. La tasa de cambio extrangera tiene diferentes efectos dependiendo de si las firmas producen bajos rendimientos a escalas constantes o decrecientes.ABSTRACT:This paper examines the systematic effect of the exchange rate volatility, when a local government has to evaluate linear and quadratic strategic trade policies. The exercise is realized for both Cournot and Bertrand markets fashions. The model proves that the linear or quadratic scheme have the same effect on the countries´ social welfare, and that the volatility of the domestic exchange rate leads governments to reduce export subsidies or to cutexport taxes, according to the strategic variable chosen by firms. The foreignexchange rate volatility has different effects if firms produce under constantreturn or decreasing return of scale.Comercio, Estructuras de Mercado y de Precios, Estrategia de Firma, Información e Incertidumbre.

Bilateral Transport Cost, Infrastructure, Common Bilateral Ties and Political Stability

Transport Costs are one of the most important sources of barriersto trade. Inspired by this concern, we use an ad-hoc empirical model to examinethe possible determinants of transport costs.Using a country aggregate bilateral transport costs database for 1990, wereplicate Limao and Venables (2001) and we find that the effect of their infrastructureindex on transport costs is not robust. Following Micco (2004) andMicco and Serebrinzky (2005) we calculate two alternative indexes of infrastructure.Using these new indexes we find that not only distance but infrastructure,political stability, common bilateral ties and open sky agreements as wellare other important channels through which transport costs can be reduced.**Los costos de transporte son una de las más importantes fuentesde barreras al comercio. Inspirados por este aspecto, utilizamos un modeloempírico ad-hoc con el fin de examinar los posibles determinantes de los costosde transporte.Utilizando una base de datos de costos de transporte bilaterales para el año1990, replicamos el trabajo de Limao y Venables (2001) y encontramos queel efecto de su índice de infraestructura sobre los costos de transporte no esrobusto. Siguiendo a Micco (2004) y Micco y Serebrinzky (2005) calculamosdos índices alternativos de infraestructura. Utilizando estos índices encontramosque aparte de la distancia, la infraestructura, la estabilidad política, lasrelaciones bilaterales comunes y los acuerdos de cielos abiertos son otros importantescanales mediante los cuales los costos de transporte pueden reducirse.transport costs, infrastructure.**costos de transporte, infraestructura.

Energy Saving Innovations, Non-Exhaustible Sources of Energy and Long-Run: What Would Happen if we Run Out of Oil?

We formulate and solve a model of factor saving technological improvementconsidering three factors of production: labor, capital and energy.The productive activities have three main characteristics: first, in order to usecapital goods firms need energy; second, there are two sources of energy: nonexhaustibleand exhaustible; third, capital goods can be of different qualitiesand the quality of these goods can be changed along two dimensions-reducingthe need of energy or changing the source of energy used in the productionprocess. The economy goes through three stages of development after industrialization.In the first one, firms make use of exhaustible energy and theefficiency in the use of energy is constant. In the second stage, as the price ofenergy grows the efficiency in its use is increased. In the third stage, the price ofexhaustible sources is so high that firms have incentives to use non-exhaustiblesources of energy. During this stage the price of energy is constant. In this setup, the end of the oil age has level effects on consumption and output but itdoes not cause the collapse of the economic system.**Se formula y resuelve un modelo de cambio tecnológico ahorradorde factores de producción que considera tres factores: capital, trabajo yenergía. El modelo cuenta con características específicas con respecto a la interacción entre la energía (la cual, de acuerdo a su fuente puede ser renovabley no renovable) y el capital. Una vez esta economía se ha definido, se suponeque evoluciona en tres etapas luego de su industrialización, durante las cualesel carácter renovable o no renovable de la energía influye su precio relativo,eficiencia y afecta también el nivel agregado de consumo y producción de laeconomía, sin que esta evolución lleve al colapso del sistema económico.non-exhaustible energy, energy saving innovations, economicgrowth.**energía renovable, innovaciones ahorradoras de energía, crecimientoeconómico.

Adding one risk to another: generalizing the unavoidable (background) risk

ResumenEste artículo ofrece una generalización del modelo de riezgo subyacente. En primer lugar, se relajan los supuestos de independencia. En segundo lugar, se adopta una forma funcional general. Tercero, se adopta un tipo de riesgo general. Adicionalmente se presenta una nueva forma general de riesgo subyacente.AbstractThis paper provides a complete generalization of the background risk models. In so doing, first, it relaxes the independence assumption. Second, it adopts a general functional form. Third, it adopts a general type of risk. Furthermore, it introduces a new general form of background risk.Background risk, uncertainty

Does High Unemployment Rate Result in a High Divorce Rate?: A Test for Japan

The purpose of this paper is to examine if the increase in the unemploymentrate has any effect on the divorce rate. We use time series data andcross section data for the whole of Japan in order to examine this assertion.We also include crime rate and average working hours as explanatory variables.We conducted cointegration analysis to avoid spurious correlation for the timeseries data. We apply OLS for the time series and cross section data. The resultssuggest a positive correlation between the unemployment rate and thedivorce rate. We also confirm that the influence of unemployment over divorceis immediate.**El objetivo de este artículo es determinar si el incremento en latasa de desempleo tiene algún efecto sobre la tasa de divorcios. Con este finse utilizan series de tiempo y datos de corte transversal para Japón. Tambiénse incluyen la tasa de crímenes y el promedio de las horas trabajadas comovariables explicativas. Adicionalmente se efectúa análisis de cointegración conel fin de evitar relaciones espúreas entre las series de tiempo. Los resultadossugieren que existe una correlación positiva entre la tasa de desempleo y la tasade divorcios. También confirmamos que existe una relación cronológica cercanaentre el desempleo y el divorcio.unemployment, marital dissolution.**desempleo, divorcio.

Tests of the functional form, the substitution effect, and the wealth effect of Mexico´s money demand function

M1, M2, and M3 demands in Mexico are positively influenced by output and stock prices and negatively associated with the saving rate, the U.S. interest rate, and the expected inflation rate. Peso depreciation affects M1 demand negatively and M2 and M3 demands positively. The log-linear form cannot be rejected for M1 demand and can be rejected for M2 and M3 demands, while the linear form can be rejected for M1, M2, and M3 demands. The CUSUMSQ test shows that M1, M2, and M3 demands are stable; while the CUSUM test indicates stability in M1 and M3 demands and instability in M2 demand.Box-Cox transformation, currency substitution, wealth effect,stability tests

Recent macroeconomic performance in colombia: what went wrong?

Al finalizar la d�cada anterior la actividad real en Colombia experiment� la m�s aguda recesi�n de los �ltimos 50 a�os. Para explicar este fen�meno, postulamos un modelo VAR estructural no-triangular que describe la din�mica de la producci�n, los precios, el desempleo y los salarios durante las �ltimas dos d�cadas. La evidencia sugiere que, en el largo plazo, la pol�tica monetaria ha sido neutral con respecto al producto y la desempleo, mientras que la principal raz�n para el incremento de �ste �ltimo se explica por la forma en que se han determinado los salarios (formaci�n de expectativas hacia atr�s) y el incremento de los costos no salariales.structural VAR, unemployment, monetary policy, wages, nonwage labour costs, expectations