Product variety, competition and economic growth

In this paper, we study the relationship between competition and economic growth using a model of economic development through the creation of new sectors. In our model, competition has both an intra- and an inter-sector component. We find that the best conditions for economic development are achieved when a suitable ratio of inter- to intra-sector competition is achieved. This ratio constitutes a compromise between providing a temporary monopoly to the first entrepreneur (low inter-sector competition) and creating enough imitation to expand the sector (intra-sector competition).     

On the nonexistence of recursive equilibrium in stochastic OLG economies

We study a class of stochastic Overlapping generations (OLG) economies that have one-memory equilibria, that is equilibria that are determined by the current and past realizations of the states of uncertainty. This class is negligible, but important. In particular, it contains all the known examples of nonexistence of recursive equilibrium. We show that, within this restricted domain, the existence of recursive equilibrium is actually typical, and such examples are therefore nonrobust. We thank Felix Kubler, Herakles Polemarchakis and Steve Spear for many useful discussions. This paper was started while the first author was visiting Columbia Business School.     

Trade and revelation of information

We consider an economy with asymmetric information and two types of agents, fully informed and uninformed. Uninformed agents update their information observing equilibrium prices and the equilibrium levels of other agents’ excess demand. We show that, for a generic set of economies, there are rational expectations equilibria which are partially revealing on an open, dense set of signals of positive Lebesgue measure, provided that the dimension of the signal space is sufficiently larger than the dimension of the commodity space.     

De-hubbing of airports and their recovery patterns

The paper analyzes cases of de-hubbing in air transport between 1997 and 2009. It initially addresses the conditions to be met for airports to be identified as de-hubbing cases. Second, it examines what happens after de-hubbing by clustering the cases into homogenous groups that show that, on average, airports that experienced de-hubbing did not recover their original traffic within five years and that de-hubbing is likely to be irreversible. When hub carriers were replaced at least partially by low-cost carriers, airports on average recovered faster. De-hubbing adversely affects the number of destinations served less severely than the seats offered by carriers.     

The spatial sorting and matching of skills and firms

Abstract .  In this paper we make use of a matched employer-employee database for Italy to look at the spatial distribution of wages. Using this rich database we aim to open up the black box of agglomeration economies exploiting the micro dimension of interaction among economic agents, both individuals and firms. We provide evidence that firm size and, especially, skills are sorted across space and account for a large portion of the spatial wage variation. Our data also support the assortative matching hypothesis, which we show not to be driven by co-location of good workers and firms. Finally, we point out that assortative matching is negatively related to local market size.     

“Rules of thumb” for sovereign debt crises

This paper investigates the economic and political conditions that are associated to the occurrence of a sovereign debt crisis. We use a new statistical approach (Classification and Regression Tree) that allows us to derive a collection of “rules of thumb” that help identify the typical characteristics of defaulters. We find that not all crises are equal: they differ depending on whether the government faces insolvency, illiquidity, or various macroeconomic risks. We also characterize the set of fundamentals that can be associated with a relatively “risk-free” zone. This classification is important for discussing appropriate policy options to prevent crises and improve response time and prediction.     

Identification and dimension of the NAIRU

In this paper, we have re-examined the identification of the NAIRU and presented a well-defined reduced form for analysing the equilibrium unemployment rate, using a cointegrated VAR model. We have stated that the NAIRU estimates using the conventional reduced form (or Phillips curve) models are misleading since the natural rate of unemployment cannot be considered as a fixed point calling for the ceteris paribus assumption for all the data involved. This implies that the NAIRU estimates are unable to provide valuable information on the labour market status.     

Measuring and forecasting regional environmental and economic efficiency in Italy

Environmental and economic efficiency has being receiving growing attention among researchers. In general terms, this concept is related to the capability of the economic systems to employ natural resources efficiently, so as to increase economic and human wealth. This clearly implies that both the economic and ecological aspects of decisions ought to be considered. Bearing this in mind, this article considers economic and ecological performance together, by applying data envelopment analysis and the Malmquist productivity index to investigate the efficiency of the 20 Italian regions from 2004 to 2011. The results reveal that the northern regions have been more efficient than the southern ones, highlighting the strong geographical differences between the two. Furthermore, this article uses the grey system theory to forecast regional, economic and environmental efficiency. The results of the forecasting analysis show that the north–south duality remains strong and will possibly increase since the regions in the south get worse in term of environmental and economic efficiency.     

A dynamic model of R&D competition

This study considers a dynamic model of R&D competition in a situation of no uncertainty with identical firms in a perfect foresight. We are going to find out about the effects of firms' absorptive capacity on R&D strategies in the presence of technological spillovers. The conditions for the existence and uniqueness of a feedback–Nash equilibrium on firms' R&D expense will be also discussed. Numerical simulations will show as the introduction of the absorptive capacity reduces the impact of spillovers degree on firms' R&D strategies.     

Productivity, terms of trade and the ‘home market effect’

This paper analyzes the international transmission and welfare implications of productivity gains and changes in market size when macroeconomic adjustment occurs both along the intensive margin of trade (changes in the relative price of existing varieties of tradable goods) and the extensive margin (creation and destruction of varieties). We draw a distinction between productivity gains that enhance manufacturing efficiency and gains that lower the cost of firms' entry and of product differentiation. Countries with lower manufacturing costs have higher GDP but supply their products at lower international prices. Instead, countries with lower entry costs supply a larger array of goods at improved terms of trade. Output growth driven by demographic expansions, as well as government spending, is associated with an improvement in international relative prices and firms' entry. While trade liberalization may result in a smaller array of goods available to consumers, efficiency gains from deeper economic integration benefit consumers via lower goods prices. The international transmission mechanism and the welfare spillovers vary under different asset market structures, depending on trade costs, the elasticity of labor supply, and consumers' taste for varieties.