GARCH models and Stochastic Volatility (SV) models can both be used to describe unobserved volatility in asset returns. We consider the issue of testing a GARCH model against an SV model. For that purpose, we propose a new and parsimonious GARCH-t model with an additional restricted moving...

We study how knowledge about the social network of an individual researcher, as embodied in his coauthor relations, helps us in developing a more accurate prediction of his or her future productivity. We find that incorporating information about coauthor networks leads to a modest improvement in...

The matching of individuals in teams is a key element in the functioning of an economy. The network of social ties can potentially transmit important information on abilities and reputations and also help mitigate matching frictions by facilitating interactions among "screened" individuals. We...

We study the evolution of social distance among economists over the period 1970–2000. While the number of economists has more than doubled, the distance between them, which was already small, has declined significantly. The key to understanding the short average distances is the observation...

This discussion paper has resulted in a publication in the <A href="http://aa4pq3kw5l.search.serialssolutions.com/directLink?&atitle=Economics%3A%20An%20Emerging%20Small%20World&author=Sanjeev%20Goyal%3B%20Marco%20J%20van%20der%20Leij%3B%20José%20Luis%20Moraga%2DGonzález&issn=00223808&title=The%20Journal%20of%20Political%20Economy&volume=114&issue=2&date=20060401&spage=403&id=doi:&sid=ProQ_ss&genre=article&lang=en">'Journal of Political Economy'</A>.<P>This paper examines the small world hypothesis. The first part of the paper presents empirical evidence on the evolution of a particular world: the world of journal publishing economists during the period...</p></a>

This paper examines the small world hypothesis. The first part of the paper presents empirical evidence on the evolution of a particular world: the world of journal publishing economists during the period 1970-2000. We find that in the 1970's the world of economics was a collection of islands....

In this paper we test the celebrated `Strength of weak ties' theory of Granovetter (1973). We test two hypotheses on the network structure in a data set of collaborating economists. While we find support for the hypothesis of transitivity of strong ties, we reject the hypothesis that weak ties...

This discussion paper led to a publication in the <A href="http://www.degruyter.com/view/j/rne.2011.10.2/rne.2011.10.2.1278/rne.2011.10.2.1278.xml">'Review of Network Economics'</A>, 2011, 10(2), 1-20.<P> In this paper we test the celebrated `Strength of weak ties' theory of Granovetter (1973). We test two hypotheses on the network structure in a data set of collaborating economists. While we find...</p></a>

We investigate whether the prospect of redistribution hinders the formation of efficiency-enhancing groups. We conduct an experiment in a Kenyan slum, Ugandan villages, and a UK university town. We test, in an anonymous setting with no feedback, whether subjects join a group that increases their...

We investigate whether social structure helps or hinders factor allocation using unusually rich data from the Gambia. Evidence indicates that land available for cultivation is allocated unequally across households; and that factor transfers are more common between neighbors, co-ethnics, and...