Self-employment and labour market transitions: a multiple state model

In this paper we estimate a multiple state transition model for the UK describing transitions in and out three possible labour market states: self-employment, paid employment and unemployment. This enables us to assess the effect of demographic characteristics as well as time changing economics conditions on the probabilities of exiting and entering each different state. A reduced form model is estimated allowing for unobservable individual heterogeneity. The results are consistent with the hypothesis of a deterioration of the labour market conditions generating an increase in the self-employment rates in adverse economic conditions. However unemployment duration generates a loss on human capital that reduce the probabilities of switching to self-employment. It appears also that -family background and education play and important role in determining the transition probabilities. Medium level educated individuals are the most likely to become self-employed

Living on apples - anthropogenic influence on microbial communities of apple fruits

Microbial communities on non-processed foods are complex with unknown effects on food quality and human health. It is generally assumed that the ecology of the microflora associated with apples reflects the environment of the orchard, handling, harvesting, and storage. We performed a comparative field trial to assess how anthropogenic factors, such as organic and conventional farming practices, influence the microbial community of apple fruits. Apples are an economically important crop in Switzerland. In 2004, we harvested apple fruits cv. Golden Delicious of five pairs of organic/ conventional farms at five different locations in Switzerland. We combined classical microbiological methods and genetic tools to characterize the cultivable and uncultivable microflora of apple fruits. Morphologically distinct mold and yeast colonies were recovered from apple fruit surface (epiphytes) or from underneath the skin (endophytes) and recorded on nutrient agar. We also started to develop culture-independent molecular DNA-techniques (e.g. PCR of internal transcribed spacer region, ITS) for species identification and fungal community studies. Several white and red/pink yeasts and yeastlike fungi were the predominant epiphytes. Morphologically different molds formed almost exclusively the endophytic microflora. The yeast-like fungi were more abundantly and more frequently found on organic apple fruits whereas red/pink yeasts prevailed on conventional fruits. We found higher numbers of endophytic molds and more morphological types in organic fruits. These results suggest that the microbial community of apple fruits adapts to the farming practice, a feature which might be useful for authenticity and food quality

Testing labour supply and hours constraints.

This paper provides empirical evidence on the assumption that individuals freely decide the number of hours they work at a given wage, using US data on prime age males from the National Longitudinal Survey of Youth. Two types of individuals are considered: those who change job between two consecutive periods and those who do not. We estimate an endogenous switching labour supply equation consistent with a life-cycle model under uncertainty. In this context the endogeneity of movements, ignored in previous analysis, proves to be crucial to get consistent estimates. The results confirm that individuals are constrained in the number of hours they work on a given job and that the intertemporal substitution elasticities are usually upward biased when ignoring the possibility of some groups of individuals being off their labour supply curves.Job changes; Labour supply; Wage elasticties; Hours constrainsts;

Missing observation analysis for matrix-variate time series data

Bayesian inference is developed for matrix-variate dynamic linear models (MV-DLMs), in order to allow missing observation analysis, of any sub-vector or sub-matrix of the observation time series matrix. We propose modifications of the inverted Wishart and matrix t distributions, replacing the scalar degrees of freedom by a diagonal matrix of degrees of freedom. The MV-DLM is then re-defined and modifications of the updating algorithm for missing observations are suggested

Inconsistencies in the application of harmonic analysis to pulsating stars

Using ultra-precise data from space instrumentation we found that the underlying functions of stellar light curves from some AF pul- sating stars are non-analytic, and consequently their Fourier expansion is not guaranteed. This result demonstrates that periodograms do not provide a mathematically consistent estimator of the frequency content for this kind of variable stars. More importantly, this constitutes the first counterexample against the current paradigm which considers that any physical process is described by a contin- uous (band-limited) function that is infinitely differentiable.Comment: 9 pages, 8 figure

Computing abuse related damages in the case of new entry: An illustration for the Directory Enquiry Services market

A number of European countries, among which the UK and Spain, have opened up their Directory Enquiry Services (DQs, or 118AB) market to competition. We analyse the Spanish case, where both local and foreign firms challenged the incumbent as of April 2003. We argue that the incumbent had the ability to abuse its dominant position, and that it was a perfectly rational strategy. In short,the incumbent raised its rivals' costs directly by providing an inferior quality version of the (essential) input, namely the incumbent's subscribers' database. We illustrate how it is possible to quantify the effect of abuse in situation were the entrant has no previous history in the market. To do this, we use the UK experience to construct the relevant counterfactual, that is the "but for abuse" scenario. After controlling for relative prices and advertising intensity, we find that one of the foreign entrants achieved a Spanish market share of only half of what it would have been in the absence of abuse.competition policy, abuse of dominance, telecommunications

Complete factorization of equations of motion for generalized scalar field theories

We demonstrate that the complete factorization of equations of motion into first-order differential equations can be obtained for real and complex scalar field theories with non-canonical dynamics.Comment: 5 pages; version published in EP