Evolution of trade patterns in the new EU member states

The paper analyses the evolution of the trade specialization pattern in the new EU member states. Relying on the empirical approach of the Markov transition matrices it analyses both the changes in the external shape of the distribution of comparative advantages and the intra‐distribution dynamics. The new members show a dynamic trade pattern: they gained comparative advantages relatively fast in sectors in which they were lagging behind at the beginning of the transition, notably in some ‘high tech’ products. In addition, many specialization improvements occurred in those items for which world demand expanded at the fastest rate over the nineties.     

Fair ranking of teachers

Economic theory suggests that it is optimal to reward teachers depending on the relative performance of their students. We develop an econometric approach, based on stochastic frontier analysis, to construct a fair ranking that accounts for the socio-economic background of students and schools and the imprecision inherent in achievement data. Using German PIRLS (IGLU) data, we exploit the hierarchical structure of the data to estimate the efficiency of each teacher. A parsimonious set of control variables suffices to get a “fair” estimate of unobserved teacher quality. A Hausman–Taylor type estimator is the preferred estimator because teacher efficiency and some exogenous variables may be correlated.     

Explaining momentum profits with an epidemic diffusion model

We show that information diffusion is a function of its dissemination and assimilation. Whereas dissemniation is a function of observable factors such as volume and price volatility, assimilation is dependent on unobservable factors such as the usefulness and reliability of information. We find that buying low volume (or low volatility) past losers and shortselling low volume (or low volatility) past winners generates a positive net return across the entire sample period and especially during bear markets. Second, buying high volatility past winners and shortselling high volatility past losers generates a positive net return, especially during bear markets.