Jobfinding and wages when longrun unemployment is really long : the case of Spain

This paper uses the "Encuesta de Condiciones de Vida Y Trabajoll (ECVT)·· a survey of the labor force activity of over 61,000 persons in Spain in 1985 when unemployment exceeded 20%--to examine the effect of unemployrnent insurance (UI) and family status on longrun joblessness. It finds that (1)duratían of joblessness 1s 50me 30% longer for those eligible for UI benefits than for those ineligible for UI; (2) the longterm unemployed are disproportionately secondary workers for whom the family serves as a form of welfare; (3) hazard rates linking the chances of jobfinding to duration of unemployment in the 1981-85 period of massive joblessness did not decline with duration; (4) the length of unemployment spells reduces wages moderately but has huge effect on the probability that re-employed workers take secondary sector jobs; (5) the UI eligible earn more and are more likely to gain regular full-time jobs than those ineligible for UI, congruent with the additional months of Job search associated with UI. The estimated effects of duratían on the hazard and on earnings are consistent with the implications of labor supply and search analysis but not with the view that long unemployment spells create a class of unemployables. Our results imply a sizeable reduction in longterm unemployment with economic recovery

The spin glass-antiferromagnetism competition in Kondo-lattice systems in the presence of a transverse applied magnetic field

A theory is proposed to describe the competition among antiferromagnetism (AF), spin glass (SG) and Kondo effect. The model describes two Kondo sublattices with an intrasite Kondo interaction strength $J_{K}$ and a random Gaussian interlattice interaction in the presence of a transverse field $\Gamma$. The $\Gamma$ field is introduced as a quantum mechanism to produce spin flipping and the random coupling has average $-2J_0/N$ and variance $32 J^{2}/N$. The path integral formalism with Grassmann fields is used to study this fermionic problem, in which the disorder is treated within the framework of the replica trick. The free energy and the order parameters are obtained using the static ansatz. In this many parameters problem, we choose $J_0/J \approx (J_{K}/J)^{2}$ and $\Gamma/J \approx (J_{K}/J)^{2}$ to allow a better comparison with the experimental findings. The obtained phase diagram has not only the same sequence as the experimental one for $Ce_{2}Au_{1-x}Co_{x}Si_{3}$, but mainly, it also shows a qualitative agreement concerning the behavior of the freezing temperature and the Neel temperature which decreases until a Quantum Critical Point (QCP).Comment: 4 pages, 1 figure, accepted for publication in Physica

Blind Multiclass Ensemble Classification

The rising interest in pattern recognition and data analytics has spurred the development of innovative machine learning algorithms and tools. However, as each algorithm has its strengths and limitations, one is motivated to judiciously fuse multiple algorithms in order to find the "best" performing one, for a given dataset. Ensemble learning aims at such high-performance meta-algorithm, by combining the outputs from multiple algorithms. The present work introduces a blind scheme for learning from ensembles of classifiers, using a moment matching method that leverages joint tensor and matrix factorization. Blind refers to the combiner who has no knowledge of the ground-truth labels that each classifier has been trained on. A rigorous performance analysis is derived and the proposed scheme is evaluated on synthetic and real datasets.Comment: To appear in IEEE Transactions in Signal Processin

Matrix completion and extrapolation via kernel regression

Matrix completion and extrapolation (MCEX) are dealt with here over reproducing kernel Hilbert spaces (RKHSs) in order to account for prior information present in the available data. Aiming at a faster and low-complexity solver, the task is formulated as a kernel ridge regression. The resultant MCEX algorithm can also afford online implementation, while the class of kernel functions also encompasses several existing approaches to MC with prior information. Numerical tests on synthetic and real datasets show that the novel approach performs faster than widespread methods such as alternating least squares (ALS) or stochastic gradient descent (SGD), and that the recovery error is reduced, especially when dealing with noisy data

Spin glass freezing in Kondo lattice compounds

It is presented a theory that describes a spin glass phase at finite temperatures in Kondo lattice systems with an additional RKKY interaction represented by long range, random couplings among localized spins like in the Sherrington- Kirkpatrick (SK) spin glass model. The problem is studied within the functional integral formalism where the spin operators are represented by bilinear combinations of fermionic (anticommuting) Grassmann variables. The Kondo and spin glass transitions are both described with the mean field like static ansatz that reproduces good results in the two well known limits. At high temperatures and low values of the Kondo coupling there is a paramagnetic (disordered) phase with vanishing Kondo and spin glass order parameters. By lowering the temperature a second order transition line is found at Tsg to a spin glass phase. For larger values of the Kondo coupling there is a second order transition line at roughly Tk to a Kondo ordered state. For T<Tsg the transition between the Kondo and spin glass phases becomes first order.Comment: 21 pages, 1 figure, to appear on Phys. Rev.

Downward Wage Rigidities and Other Firms’ Responses to an Economic Slowdown: Evidence from a Survey of Colombian Firms

This paper uses a wage setting survey of 1,305 Colombian firms to explore the nature and sources of wage rigidities. This is the first study of a non-European emerging economy that uses evidence from a survey of firms to analyse this topic. The survey was carried out during the first half of 2009, when the Colombian economy was showing signs of a slowdown in economic activity and increasing unemployment. The sample is fully representative of the population under study. The results provide evidence of nominal and real downward wage rigidities in the country. The most important factor in not reducing base wages during an economic slowdown is to avoid the loss of more experienced and productive workers, which is related to the efficiency wage theory in its adverse selection version. In addition, ordered logit regressions were used to determine what factors are related to wage rigidities. The findings indicate that, in general, permanent contracts, workforce composition, labour intensity and the presence of collective agreements play an important role in explaining wage rigidities in the country.Wage rigidities, survey evidence, efficiency wages, Colombia, labour market, ordered logit. Classification JEL: C25, J30, J50

Wage Adjustment Practices and the Link between Price and Wages: Survey Evidence from Colombian Firms

The aim of this paper is to explore firms’ wage adjustment practices in the Colombian formal labor market; specifically, the timing and frequency of wage increases, as well as the link between wage and price changes. To this end, we use an ad hoc survey of 1,305 small, medium and large firms belonging to all economic sectors, except the public sector. The results show most of the firms adjust base wages annually, mainly during the first quarter, which suggests wage changes in Colombia are time-dependent. Also, wage increases were concentrated around observed inflation and none of the firms cut wages. Moreover, factors associated with the performance of firms and workers alike are the main determinants of wage adjustments. Regarding the link between wages and price changes, econometric results indicate this relationship is stronger in sectors where labor costs represent a higher share of total costs and in firms operating in sectors with higher labor productivity.Wage increases, labor market, survey evidence, logit models, Colombia. Classification JEL: D22, J30, C25.

Are wages rigid in Colombia?: Empirical evidence based on a sample of wages at the firm level

This paper uses Colombian data at the firm level for the period 1999 to 2006 to provide microeconomic evidence on the existence and extent of downward nominal wage rigidity. To conduct the analysis, we use a rich panel of firms for white and blue collar workers, consisting of 1517 firms for the former and 781 firms for the latter. The presence of wage rigidity is determined by means of three statistic techniques used in recent literature, such as the analysis of the histograms of the distribution of wage changes, the LSW statistic and the Kahn test. The results suggest the existence of downward nominal wage rigidities; it is worth mentioning that rigidity is higher for blue collar workers than white collar workers, since the increase in the wages of the blue workers is generally done by taking into account the change in the minimum wage, which is why a higher rigidity would be expected.Wage rigidity, Kahn test, LSW Statistic, Colombia. Classification JEL: J31, E24, C23

Spin Glass and antiferromagnetism in Kondo lattice disordered systems

The competition between spin glass (SG), antiferromagnetism (AF) and Kondo effect is studied here in a model which consists of two Kondo sublattices with a gaussian random interaction between spins in differents sublattices with an antiferromagnetic mean Jo and standard deviation J. In the present approach there is no hopping of the conduction electrons between the sublattices and only spins in different sublattices can interact. The problem is formulated in the path integral formalism where the spin operators are expressed as bilinear combinations of Grassmann fields which can be solved at mean field level within the static approximation and the replica symmetry ansatz. The obtained phase diagram shows the sequence of phases SG, AF and Kondo state for increasing Kondo coupling. This sequence agrees qualitatively with experimental data of the Ce_{2} Au_{1-x} Co_{x} Si_{3} compound.Comment: 7 pages, 1 figure, submitted to EPJ