THE GINI CONCENTRATION INDEX: A REVIEW OF THE INFERENCE LITERATURE

More than a century ago, Corrado Gini proposed his well-known concentration index for measuring the degree of inequality in the distribution of income and wealth. His index is still extremely relevant and widely used in several fields of research and application. In this paper, we focus on the inferential properties of the Gini index, and discuss the main directions of analysis proposed in the literature. The aim of the paper is to provide a comprehensive review of the main developments on the inferential aspects of the Gini concentration ratio. We feel that this work can provide a valuable contribution to those scholars who are approaching the large amount of literature on the inferential properties of the Gini index.     

International Capital Flows in the Model with Limited Commitment and Incomplete Markets

Recent literature has proposed two alternative types of financial frictions, i.e., limited commitment and incomplete markets, to explain the empirical patterns of international capital flows between developed and developing countries in the past two decades. This paper integrates these two frictions into a two-country overlapping-generations framework to facilitate a direct comparison of their respective effects. In our model, limited commitment distorts the investment made by agents with different productivity, which creates a wedge between the interest rates on equity capital vs. credit capital; while incomplete markets distort the investment among projects with different riskiness, which creates a wedge between the risk-free rate and the mean rate of return to risky capital. We show that the two approaches are observationally equivalent with respect to their implications for international capital flows, production efficiency, and aggregate output.     

What’s at Stake in Securitising Climate Change? Towards a Differentiated Approach

Climate change has been successfully represented as a security concern to such an extent that it is firmly established on the political agenda, even though the implementation of concrete policies is disputed. In this paper, we develop an analytical framework to better trace the process of securitising climate change and assess its normative implications. We establish a typology of six climate security discourses on the basis of two dimensions: three levels of referent objects and two logics of securitisation, one that corresponds to the original Copenhagen School framework and one where the threat takes the form of the invocation of risk. We find that there are significant differences in the relative importance of the resulting climate security discourses in Germany and the US, but that normatively, all discourses come with their own problems, which calls for more detailed scrutiny and assessment of climate security discourses and their political effects.     

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.     

Accomplice Witnesses and Organized Crime: Theory and Evidence from Italy

We develop an agency model of organized crime accounting for the main trade‐offs involved in the introduction of an accomplice‐witness program. We characterize the optimal policy and identify its main determinants in a framework where public officials can be dishonest. Our predictions are tested by using data for Italy before and after the introduction of the 1991 accomplice‐witness program. As predicted by the model and the earlier antitrust literature, the program appears to have strengthened deterrence and enhanced prosecution. Moreover, consistent with a novel prediction of our theory, the evidence suggests that the program efficacy is affected by the judicial system efficiency.     

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.     

Do interest groups affect US immigration policy?

While anecdotal evidence suggests that interest groups play a key role in shaping immigration policy, there is no systematic empirical analysis of this issue. In this paper, we construct an industry-level dataset for the United States, by combining information on the number of temporary work visas with data on lobbying activity associated with immigration. We find robust evidence that both pro- and anti-immigration interest groups play a statistically significant and economically relevant role in shaping migration policy across sectors. Barriers to migration are lower in sectors in which business interest groups incur larger lobbying expenditures and higher in sectors where labor unions are more important.