Temporary help agencies and occupational mobility

This paper focuses upon the effect of Temporary Help Agencies (THAs) on occupational mobility through a comparison of the job-to-job upgrading chances of THA and non-THA workers. A screening approach to the role of these labor "brokers" suggests that agency workers can expect greater upgrading chances between two different occupations. Results obtained from a sample of Spanish workers show that working through these intermediaries allows workers in intermediate occupational levels to avoid occupational demotions more easily than non-THA ones. Moreover, THAs improve the probability for high-skilled workers of achieving a permanent contract. The empirical analysis demonstrates that the existence of self-selection is an important explanation for increased occupational mobility among THA workers in Spain

The nineties in Spain: too much flexibility in the youth labour market?

This paper examines movements into and out of employment in the Spanish youth labour market throughout the nineties. We analyze how differences in personal and economic circumstances influence such movements. In addition, we consider the importance of duration dependence in determining them. Our main findings are that: (i) Very young workers, women and those with lower qualification levels are more likely to be affected by high labour turnover; (ii) The existence of unobserved heterogeneity has important consequences in the unemployment hazard rate; (iii) In the 90's, employment hazard rates were substantially affected by the extensive use of fixed-term contracts, although the 1997 labour market reform seems to have reduced this hazard rate; (iv) The intervention of temporary help agencies has a positive impact on the likelihood of leaving unemployment, although only for short-term unemployed individuals; at the same time, however, the employment hazard rate is substantially higher within these agencies

Are temporary help agencies changing mobility patterns in the Spanish labour market?

This paper examines to what extent Temporary Help Agency intermediation in the labour market affects workers' transitions into and out of employment in the Spanish youth labour market throughout the nineties. Results obtained show that this intermediation presents a positive impact on the likelihood of leaving unemployment, although only for short-term unemployed individuals; at the same time, however, the employment hazard rate is substantially higher for agency workers. We also find that employment hazard rates were substantially affected in the 90's by the extensive use of fixed-term contracts, although the 1997 labour market reform is found to reduce this hazard rate. Finally, very young workers, women and those with lower qualification levels are more likely to be affected by higher labour turnover

Transitions into permanent employment in Spain : an empirical analysis for young workers

We analyze the Spanish temporary workers’ transitions into permanent employment and to what extent those who become unemployed are able to achieve a permanent job. Our focus is placed on the role of the individual’s sequence of temporary contracts on the probability of moving from temporary into permanent employment. We apply multiplespell duration techniques to a longitudinal dataset of temporary workers obtained from Social Security records for the period 1996-2003. We basically find that even though transitions into permanent employment increase with tenure, temporary jobs do not constitute stepping stones towards permanent employment, since the probability of obtaining a permanent job decreases with repeated temporary jobs. Results also show that individuals with high duration of unemployment flow into permanent work less frequently

Enabling Practical IPsec authentication for the Internet

On the Move to Meaningful Internet Systems 2006: OTM 2006 Workshops (First International Workshop on Information Security (IS'06), OTM Federated Conferences and workshops). Montpellier, Oct,/Nov. 2006There is a strong consensus about the need for IPsec, although its use is not widespread for end-to-end communications. One of the main reasons for this is the difficulty for authenticating two end-hosts that do not share a secret or do not rely on a common Certification Authority. In this paper we propose a modification to IKE to use reverse DNS and DNSSEC (named DNSSEC-to-IKE) to provide end-to-end authentication to Internet hosts that do not share any secret, without requiring the deployment of a new infrastructure. We perform a comparative analysis in terms of requirements, provided security and performance with state-of-the-art IKE authentication methods and with a recent proposal for IPv6 based on CGA. We conclude that DNSSEC-to-IKE enables the use of IPsec in a broad range of scenarios in which it was not applicable, at the price of offering slightly less security and incurring in higher performance costs.Universidad de Montpellier IIPublicad

TEMPORARY HELP AGENCIES AND OCCUPATIONAL MOBILITY

This paper focuses upon the effect of Temporary Help Agencies (THAs) on occupational mobility through a comparison of the job-to-job upgrading chances of THA and non-THA workers. A screening approach to the role of these labor “brokers” suggests that agency workers can expect greater upgrading chances between two different occupations. Results obtained from a sample of Spanish workers show that working through these intermediaries allows workers in intermediate occupational levels to avoid occupational demotions more easily than non-THA ones. Moreover, THAs improve the probability for high-skilled workers of achieving a permanent contract. The empirical analysis demonstrates that the existence of self-selection is an important explanation for increased occupational mobility among THA workers in Spain.

Temporary help agencies and workers' occupational mobility

This paper focuses on the occupational mobility of temporary help agency workers by studying their job-to-job upgrading chances as opposed to those who have not been hired through these intermediaries. A screening approach to the role of those labor ‘brokers’ suggests that agency workers may expect greater chances of upgrading from one occupation to another. Results obtained with a sample of Spanish workers show that working through those intermediaries comparatively offers stronger prospects of occupational upgrading for workers of a medium qualification level. This basic result is reinforced when the existence of self-selection into this type of intermediated work is appropriately taken into account.Temporary help agencies, screening, self-selection, switching models

Astronomical Site Ranking Based on Tropospheric Wind Statistics

We present comprehensive and reliable statistics of high altitude wind speeds and the tropospheric flows at the location of five important astronomical observatories. Statistical analysis exclusively of high altitude winds point to La Palma as the most suitable site for adaptive optics, with a mean value of 22.13 m/s at the 200 mbar pressure level. La Silla is at the bottom of the ranking, with the largest average value 200 mbar wind speed(33.35 m/s). We have found a clear annual periodicity of high altitude winds for the five sites in study. We have also explored the connection of high to low altitude atmospheric winds as a first approach of the linear relationship between the average velocity of the turbulence and high altitude winds (Sarazin & Tokovinin 2001). We may conclude that high and low altitude winds show good linear relationships at the five selected sites. The highest correlation coefficients correspond to Paranal and San Pedro Martir, while La Palma and La Silla show similar high to low altitude wind connection. Mauna Kea shows the smallest degree of correlation, which suggests a weaker linear relationship. Our results support the idea of high altitude winds as a parameter for rank astronomical sites in terms of their suitability for adaptive optics, although we have no evidence for adopting the same linear coefficient at different sites. The final value of this linear coefficient at a particular site could drastically change the interpretation of high altitude wind speeds as a direct parameter for site characterization.Comment: 18 pages, 5 figures. Accepted in MNRA

Solid flow drives surface nanopatterning by ion-beam irradiation

Ion Beam Sputtering (IBS) is known to produce surface nanopatterns over macroscopic areas on a wide range of materials. However, in spite of the technological potential of this route to nanostructuring, the physical process by which these surfaces self-organize remains poorly under- stood. We have performed detailed experiments of IBS on Si substrates that validate dynamical and morphological predictions from a hydrodynamic description of the phenomenon. Our results elucidate flow of a nanoscopically thin and highly viscous surface layer, driven by the stress created by the ion-beam, as a description of the system. This type of slow relaxation is akin to flow of macroscopic solids like glaciers or lead pipes, that is driven by defect dynamics.Comment: 12 pages, 4 figure