Actual portfolios contain fewer stocks than are implied by standard financial analysis that balances the costs of diversification against the benefits in terms of the standard deviation of the returns. Suppose a safety first investor cares about downside risk and recognizes the heavy

Actual portfolios contain fewer stocks than are implied by standard financial analysis that balances the costs of diversification against the benefits in terms of the standard deviation of the returns. Suppose a safety first investor cares about downside risk and recognizes the heavytail feature...

See the article in the <I>Annals of Financial Economics</I> (2013). Volume 8, issue 2, pages 1-18.<P> In this paper, we develop a modified maximum likelihood (MML) estimator for the multiple linear regression model with underlying student t distribution. We obtain the closed form of the estimators, derive...</p></i>

Risk managers use portfolios to diversify away the unpriced risk of individual securities. In this article we compare the benefits of portfolio diversification for downside risk in case returns are normally distributed with the case of fat-tailed distributed returns. The downside risk of a...

This discussion paper led to a publication in <I>Economics Letters</I> (2014). Vol. 123(3), pages 291-294.<P> Hausman (1978) developed a widely-used model specification test that has passed the test of time. The test is based on two estimators, one being consistent under the null hypothesis but...</p></i>

Risk managers use portfolios to diversify away the unpriced risk of individual securities. In this article we compare the benefits of portfolio diversification for downside risk in case returns are normally distributed with the case of fat-tailed distributed returns. The downside risk of a...

A recent literature has emerged providing compelling evidence that a major shift in the organization of the developed economies has been taking place: away from what has been characterized as the <I>managed economy</I> towards the <I>entrepreneurial economy</I>. In particular, the empirical evidence provides...</i></i>

In this paper we investigate whether markets with heterogeneous network externalities can be locked-in by old technologies even if superior technologies are available. Heterogeneous network externalities are present when some consumers care more about the size of the market share of a good than...

Using a comprehensive international trade data set we investigate empirical regularities (known as Zipf’s Law or the rank-size rule) for the distribution of the interaction between countries as measured by revealed comparative advantage. Using the recently developed estimator by Gabaix and...

The main contribution of entrepreneurship theory to economics is to provide an account of market performance in disequilibrium but little empirical research has examined firm entry and exit in this context. We redress this by modelling the interrelationship between firm entry and exit in...