A spatial mixed Poisson framework for combination of excess-of-loss and proportional reinsurance contracts

In this paper a purely theoretical reinsurance model is presented, where the reinsurance contract is assumed to be simultaneously of an excess-of-loss and of a proportional type. The stochastic structure of the set of pairs (claim’s arrival time, claim’s size) is described by a Spatial Mixed Poisson Process. By using an invariance property of the Spatial Mixed Poisson Processes, we estimate the amount that the ceding company obtains in a fixed time interval in force of the reinsurance contract

Evaluating Job Search Programs for Old and Young Individuals: Heterogeneous Impact on Unemployment Duration

This paper exploits an area-based pilot experiment to identify average treatment effects on unemployment duration of treated individuals of two active labor market programs implemented in Portugal. We focus on the short-term heterogeneous impact on two subpopulations of unemployed individuals: young (targeted by the Inserjovem program) and old (targeted by the Reage program). We show that the latter program has a small and positive impact (reduction) on unemployment duration of workers finding a job upon participation, whereas the impact of Inserjovem is generally negative (extended durations). These results are robust to a wide variety of constructions of quasi-experimental settings and estimators. The identification of heterogeneous effects showed that the program results were less satisfactory for young workers, for those over 40 and for the less educated. Women also benefited less from the programs. The results seem to improve slightly for young workers in the 2nd semester of implementation, but they deteriorate in the medium term. The lack of wage subsidies in the Portuguese programs may explain the minor impacts obtained, when compared to similar programs

Evaluating the Effectiveness of a School-Based Intervention on Driving-Related Carbon Emissions Using Real-Time Transportation Data

The development of tools that can measure the efficiency of individual driving behaviors offers unique opportunities to encourage drivers towards more efficient driving behaviors. As states make progress towards reducing carbon emissions through the adoption of renewable energy for electricity generation, transportation remains the largest sources of carbon emissions. Although numerous local or regional campaigns have encouraged consumers to conserve energy at home and at work, less interest has been shown in encouraging drivers to adopt more energy efficient driving behaviors. In this study, a smartphone application was used to gather driving data (e.g., hard accelerations, hard braking and time over speed limit) within a university course on climate change to investigate whether environmental appeals could encourage more efficient driving behavior in students. The results show that through this intervention, average student driving scores improved by between 2 and 5% in the classes studied, with larger changes found in students who did not initially identify as having pro-environmental attitudes. These results suggest that educational programs and campaigns using real-time data on driving behavior may provide opportunities to reduce carbon emissions

Some results on stability concepts for matching models

We consider a general class of two-sided matching markets, called many-to-one matching markets with money. For a special case of these markets, where each seller owns di¤erent objects, we prove that stable outcomes cannot be characterized by the non-existence of unsatis…ed pairs. Moreover, we restore the dual lattice structure in markets with more than one seller using a connection with an assignment game.Matching, Assignment, Stability.

Wave propagation and shock formation in different magnetic structures

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave propagation as a function of the magnetic flux of the structure (i.e. two different-sized sunspots, a tiny pore and a facular region). While photospheric oscillations have similar characteristics everywhere, oscillations measured at chromospheric heights show different amplitudes, frequencies and stages of shock development depending on the observed magnetic feature. The analysis of the power and the phase spectra, together with simple theoretical modeling, lead to a series of results concerning wave propagation within the range of heights of this study. We find that, while the atmospheric cut-off frequency and the propagation properties of the different oscillating modes depend on the magnetic feature, in all the cases the power that reaches the high chromosphere above the atmospheric cut-off comes directly from the photosphere by means of linear vertical wave propagation rather than from non-linear interaction of modes.Comment: Accepted for publication in The Astrophysical Journal. 29 pages, 9 figures, 12pt, preprin

The Careers of Top Managers and Firm Openness: Internal Versus External Labour Markets

This paper studies the careers of top managers using a large panel of firms. The main objective is to empirically evaluate the role of learning and human capital acquisition in promotion dynamics along with variables capturing the formation of internal labour market (ILM) practices. We find that promotion is negatively correlated with tenure, but that there is a non-linear negative duration dependence with elapsed time since the last promotion event. Firms showing a weaker degree of ILM are less prone to promote insiders. We next take the manager's career inside a firm as a sequence of promotion decisions, and use a nested structure of the promotion decision modelled as a nested logit model. �Results show that the top manager's progression nest into four types: loser, early starter, late beginner, and champion, and that the degree of ILM as a signigicant impact on the process of learning inside the firm.

Multi-layer study of wave propagation in sunspots

We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I 10827 and the He I 10830 multiplet. From the Doppler shifts of these lines we retrieve the variation of the velocity along the line-of-sight at several heights. Phase spectra are used to obtain the relation between the oscillatory signals. Our analysis reveals standing waves at frequencies lower than 4 mHz and a continuous propagation of waves at higher frequencies, which steepen into shocks in the chromosphere when approaching the formation height of the Ca II H core. The observed non-linearities are weaker in Ca II H than in He I lines. Our analysis suggests that the Ca II H core forms at a lower height than the He I 10830 line: a time delay of about 20 s is measured between the Doppler signal detected at both wavelengths. We fit a model of linear slow magnetoacoustic wave propagation in a stratified atmosphere with radiative losses according to Newton's cooling law to the phase spectra and derive the difference in the formation height of the spectral lines. We show that the linear model describes well the wave propagation up to the formation height of Ca II H, where non-linearities start to become very important.Comment: Accepted by The Astrophysical Journa