Evaluating the effects of labour market reforms at the margin on unemployment and employment stability: the Spanish case

This study analyses the effects on unemployment and the quality of employment of the Spanish labour market reform in 2001 for the most important age groups. The content of the reform was based on the implementation of two policies: (i) a new permanent contract with lower firing costs than the ordinary one, and (ii) the reduction of the payroll taxes paid by firms to foster creation/ conversion of/ into permanent contracts. This reform extended to further groups of workers similar measures adopted in a previous reform in 1997. Using a data base of unemployed workers in the region of Madrid from January 1997 up to September 2003, and methods for non-experimental data, the results suggest that, regardless of gender, workers below 30 years are negatively affected by the reform, and workers above 55 years show positive but small effects. The influence of the reform for workers between 45 and 50 years is negligible. As regards education, graduates are more sensitive to the reform than workers with a lower level of education (primary and secondary education)

Evaluating the effects of labour market reforms at the margin on unemployment and employment stability: the Spanish case.

This study analyses the effects on unemployment and the quality of employment of the Spanish labour market reform in 2001 for the most important age groups. The content of the reform was based on the implementation of two policies: (i) a new permanent contract with lower firing costs than the ordinary one, and (ii) the reduction of the payroll taxes paid by firms to foster creation/ conversion of/ into permanent contracts. This reform extended to further groups of workers similar measures adopted in a previous reform in 1997. Using a data base of unemployed workers in the region of Madrid from January 1997 up to September 2003, and methods for non-experimental data, the results suggest that, regardless of gender, workers below 30 years are negatively affected by the reform, and workers above 55 years show positive but small effects. The influence of the reform for workers between 45 and 50 years is negligible. As regards education, graduates are more sensitive to the reform than workers with a lower level of education (primary and secondary education).

EVALUATING THE EFFECTS OF LABOUR MARKET REFORMS “AT THE MARGIN” ON UNEMPLOYMENT AND EMPLOYMENT STABILITY: THE SPANISH CASE

This study analyses the effects on unemployment and the quality of employment of the Spanish labour market reform in 2001 for the most important age groups. The content of the reform was based on the implementation of two policies: (i) a new permanent contract with lower firing costs than the ordinary one, and (ii) the reduction of the payroll taxes paid by firms to foster creation/ conversion of/ into permanent contracts. This reform extended to further groups of workers similar measures adopted in a previous reform in 1997. Using a data base of unemployed workers in the region of Madrid from January 1997 up to September 2003, and methods for non-experimental data, the results suggest that, regardless of gender, workers below 30 years are negatively affected by the reform, and workers above 55 years show positive but small effects. The influence of the reform for workers between 45 and 50 years is negligible. As regards education, graduates are more sensitive to the reform than workers with a lower level of education (primary and secondary education).

Reaction cross sections for proton scattering from stable and unstable nuclei based on a microscopic approach

Microscopic optical model potential results for reaction cross sections of proton elastic scattering are presented. The applications cover the 10-1000 MeV energy range and consider both stable and unstable nuclei. The study is based on in-medium g-matrix full-folding optical model approach with the appropriate relativistic kinematic corrections needed for the higher energy applications. The effective interactions are based on realistic NN potentials supplemented with a separable non-Hermitian term to allow optimum agreement with current NN phase-shift analyzes, particularly the inelasticities above pion production threshold. The target ground-state densities are obtained from Hartree-Fock-Bogoliubov calculations based on the finite range, density dependent Gogny force. The evaluated reaction cross sections for proton scattering are compared with measurements and their systematics is analyzed. A simple function of the total cross sections in terms of the atomic mass number is observed at high energies. At low energies, however, discrepancies with the available data are observed, being more pronounced in the lighter systems.Comment: 11 pages, 4 figures, submitted to Phys. Rev.

An in-medium full-folding model approach to quasielastic (p,n) charge-exchange reactions

A microscopic description of the quasielastic (p,n) charge-exchange reaction (here, charge-exchange scattering between analogue states) is presented and discussed. Emphasis is focused on the spin-isospin structure of the projectile-target coupling. The model is a coupled-channel extension of the full-folding optical model approach (OMP) developed for nucleon elastic scattering, where emphasis is placed on retaining the genuine off-shell behavior of realistic effective interactions in the nuclear medium. The resulting non-local optical potentials are applied to the calculation of (p,n) differential cross sections, with particular emphasis on small-angle Fermi ($\Delta S=0$) cross-sections to isobaric analog states. These parameter-free results provide a reasonable description of the $^{14}$C(p,n)-data at proton energies above $\sim$100 MeV, but deteriorate for heavier targets. These shortcomings are analyzed and possible ways to correct them are discussed.Comment: 20 pages plus 10 figures. Accepted for publication in Phys. Rev.

Nuclear halo structure from quasielastic charge-exchange reactions

Neutron and proton densities in the nuclear periphery are investigated within (p,n) charge-exchange isobar transitions. For this purpose we have developed parameter-free optical potentials with a detailed treatment of the in-medium $t_{\tau}$ part of the effective interaction. Non local coupled-channel Lane equations are solved to obtain the scattering observables. The use of conventional proton and neutron densities significantly underestimates Fermi (forward-angle) cross-sections in agreement with findings by various other groups. However, we have found model-independent densities which provide a remarkable improvement in the description of the quasielastic scattering data.The densities obtained are consistent with recent measurements at CERN in studies of the neutron-to-proton halo factor f(r)=Z$\rho_n/N\rho_p$ with antiprotons. These findings provide an alternative way to investigate the nuclear periphery, and may also help to solve the long-standing puzzle of the underestimated Fermi cross section in (p,n) charge-exchange phenomena.Comment: 5 pages and 2 figs. Presented at the Baryons-04 Conference (Palaiseau, France, Oct 2004). To appear in Nucl. Phys.

Microscopic analysis of K^+-nucleus elastic scattering based on K^+N phase shifts

We investigate $K^{+}$-nucleus elastic scattering at intermediate energies within a microscopic optical model approach. To this effect we use the current $K^{+}$-nucleon {\it (KN)} phase shifts from the Center for Nuclear Studies of the George Washington University as primary input. First, the {\it KN} phase shifts are used to generate Gel'fand-Levitan-Marchenko real and local inversion potentials. Secondly, these potentials are supplemented with a short range complex separable term in such a way that the corresponding unitary and non-unitary {\it KN} $S$ matrices are exactly reproduced. These {\it KN} potentials allow to calculate all needed on- and off-shell contributions of the $t$ matrix,the driving effective interaction in the full-folding $K^{+}$-nucleus optical model potentials reported here. Elastic scattering of positive kaons from $^{6}$Li, $^{12}$C, $^{28}$Si and $^{40}$Ca are studied at beam momenta in the range 400-1000 MeV/{$c$}, leading to a fair description of most differential and total cross section data. To complete the analysis the full-folding model, three kinds of simpler $t\rho$ calculations are considered and results discussed. We conclude that conventional medium effects, in conjunction with a proper representation of the basic {\it KN} interaction are essential for the description of $K^{+}$-nucleus phenomena.Comment: 11 pages, 1 table, 12 figures, submitted to PR

Sensitivity of nucleon-nucleus scattering to the off-shell behavior of on-shell equivalent NN potentials

The sensitivity of nucleon-nucleus elastic scattering to the off-shell behavior of realistic nucleon-nucleon interactions is investigated when on-shell equivalent nucleon-nucleon potentials are used. The study is based on applications of the full-folding optical model potential for an explicit treatment of the off-shell behavior of the nucleon-nucleon effective interaction. Applications were made at beam energies between 40 and 500 MeV for proton scattering from 40Ca and 208Pb. We use the momentum-dependent Paris potential and its local on-shell equivalent as obtained with the Gelfand-Levitan and Marchenko inversion formalism for the two nucleon Schroedinger equation. Full-folding calculations for nucleon-nucleus scattering show small fluctuations in the corresponding observables. This implies that off-shell features of the NN interaction cannot be unambiguously identified with these processes. Inversion potentials were also constructed directly from NN phase-shift data (SM94) in the 0-1.3 GeV energy range. Their use in proton-nucleus scattering above 200 MeV provide a superior description of the observables relative to those obtained from current realistic NN potentials. Limitations and scope of our findings are presented and discussed.Comment: 17 pages tightened REVTeX, 8 .ps figures, submitted to Phys. Rev.