It is generally believed that for the power of unit root tests, only the time span and not the observation frequency matters. In this paper we show that the observation frequency does matter when the high-frequency data display fat tails and volatility clustering, as is typically the case for...

The risk of investment in schooling has largely been ignored. We assess thevariance in the rate of return by surveying the international empirical literature from this freshperspective and by simulating risky earnings profiles in alternative options. choosingparameters on basis of the very...

The rational expectations hypothesis is one of the cornerstones of current economic theorising. This review discusses a number of experiments that focus on expectation formation by human subjects and analyses the implications for the rational expectations hypothesis. The experiments show that...

In a large class of hazard models with proportional unobserved heterogeneity, the distribution of the heterogeneity among survivors converges to a gamma distribution. This convergence is often rapid. We derive this result as a general result for exponential mixtures and explore its implications...

This discussion paper resulted in a publication in the 'Journal of Banking and Finance' (2013). Vol. 37, issue 12, pages 5073-5087.<P> This paper conducts a horse-race of different liquidity proxies using dynamic asset allocation strategies to evaluate the short-horizon predictive ability of...</p>

We consider the dynamic factor model where the loading matrix, the dynamic factors and the disturbances are treated as latent stochastic processes. We present empirical Bayes methods that enable the efficient shrinkage-based estimation of the loadings and the factors. We show that our estimates...

We develop models of optimal linear and non-linear income taxation with endogenous human capital formation to explore optimal education subsidies. Optimal subsidies on education ensure efficiency in human capital accumulation and thus play an important role in alleviating the tax distortions on...

This paper discusses the value that data from mobile phone providers can bring into urban analysis. The novel argument is that the pervasiveness of mobile phone telephony has transformed mobile phones from a communications device to a tool for socio-spatial research. Put simply, mobile phone...

This discussion paper resulted in a publication in the <I>Mathematical Methods of Operations Research</I> (2005). Volume 62, issue 3, pages 467-483.<P> We develop a methodology for studying "large deviations type" questions. Our approach does not require that the large deviations principle holds, and is...</p></i>

We document a consistent and robust relation between expected equity premia and common risk factors constructed on the basis of small stocks. Empirically, we show that (i) small-stock components of traditional value and momentum factors capture patterns in returns on regional and global...