Calibrating spatial models of trade

Empirical spatial models of trade that are based on a mathematical programming specification often exhibit a large discrepancy between the equilibrium solution and the observed demand, supply and levels of trade flows among countries. This discrepancy may be due to several causes. Assuming, however, that a trade model is not misspecified – in the sense that behavior of the economic agents involved in the specific commodity markets has been included in the study and that the relevant policy instruments have been properly taken into account – the cause of discrepancy may be traced either to imprecision of unit transaction costs or to imprecision in the measurement of the demand and supply functions' parameters, or both. Policy assessments based on this type of imprecise models are distorted. This paper presents a methodology for calibrating mathematical programming spatial trade models of increasing complexity, from the one-commodity case to a multi-commodity model with asymmetric slope matrices of demand and supply functions. The proposed calibration procedure identifies corrections of imperfectly measured parameters. The calibrated models generate solutions that exactly reproduce quantities produced and consumed in all countries, as well as trade flows among all pairs of countries, observed in a given base year. Such models may then serve as a springboard for assessing the impact of various policy changes on economic agents in the countries under study.     

ON TECHNOLOGY COMPETITION: A FORMAL ANALYSIS OF THE ‘SAILING-SHIP EFFECT’

One of the key features of our economies consists of the coexistence of different technologies supplying similar products and services. We often observe that an old technology is improved when a new one appears; behind this process of improvement often lies an intentional research activity. There thus begins a competition between the two technologies whose performances are improved via R&D. We focus our attention on this competition process and supply a formal model, based on the optimization of R&D expenditure of both technologies, which can describe the dynamics of the delayed overtaking of the new technology over the old one.     

Giffen goods and market making

Summary. This paper shows that information effects per se are not responsible for the Giffen goods anomaly affecting traders demands in multi asset noisy, rational expectations equilibrium markets. The role that information plays in traders strategies also matters. In a market with risk averse, uninformed traders, informed agents have a dual trading motive: speculation and market making. The former entails using prices to assess the effect of error terms; the latter requires employing them to disentangle noise traders demands within aggregate orders. In a correlated environment this complicates the signal extraction problem and may generate upward sloping demand curves. Assuming (i) that competitive, risk neutral market makers price the assets or that (ii) uninformed traders risk tolerance coefficient grows unboundedly, removes the market making component from informed traders demands rendering them well behaved in prices.Received: 30 April 2002, Revised: 3 December 2003, JEL Classification Numbers: G100, G120, G140.Support from the Barcelona Economics Program of CREA and the Ente per gli Studi Monetari e Finanziari Luigi Einaudi, are gratefully acknowledged. I thank Anat Admati, Jordi Caballé, Giacinta Cestone, and Xavier Vives for useful suggestions. The comments provided by the Associate Editor and an anonymous referee greatly improved the papers exposition.     

Migration,Friendship Ties,and Cultural Assimilation

We study immigrant assimilation by analyzing whether friendship with natives is a measure of cultural assimilation, and by investigating the formation of social ties. Using the German Socio‐Economic Panel, we find that immigrants with a German friend are more similar to natives than those without German friends, along several important dimensions, including concerns about the economy, an interest in politics, and a host of policy issues. Turning to friendship acquisition, we find that becoming employed, time spent in the host country, the birth of a child, residential mobility, and additional education acquired in the host country are significant drivers of social network variation.     

Multi-stage real option evaluation with double barrier under stochastic volatility and interest rate

Annals of Finance - This paper focuses on valuing R&D projects using a twofold compound real option by including two knock-out barriers. However, the valuation of R&D projects is...     

VRP revisited: The impact of behavioural costs in balancing standardisation and variety

The objective of this paper is to bring a new element to the academic (and industrial) debate concerning the optimum level of variety in component design in mass production companies. Many authors have explored the trade-off between functional and variety costs, and this could be considered as a well-acknowledged management issue, at least from an engineering perspective. Nevertheless, while defining the theoretically optimal level of component variety, there are other elements, more related to operators’ attitude or to operative conditions, which may intervene and prevent effective exploitation of the existing variety. These elements have been given scant attention in literature, while they may play a relevant role in real organisations.In this paper, we will present a case study and an analytic model for these “behavioural costs” in manufacturing environments, so as to show how the theoretically optimal amount of variety changes if one takes into account these aspects. Researchers (and practitioners) might leverage on this contribution in order to rejuvenate the Variety Reduction paradigm, and to increase their awareness in designing and managing mass production manufacturing processes.     

Externalities,Cross-Sectoral Spillovers and Productivity Growth

We provide an interpretation of the productivity dynamics in the manufacturing sector based on the idea of the thick market externality à la Diamond. An econometric model has been estimated which allows to disentangle the long run effects of these trading externalities from those of internal economies of scale and of aggregate industry-level economies. The results obtained—based on a cointegrated system of non-linear-error-correction equations—confirm the hypothesis that the trading externality matters. Moreover, our findings point out that the emphasis generally posited both on internal and external economies of scale is not justified.