duration dependence

We propose Bayesian inference in hazard regression models where the baseline hazard is unknown, covariate effects are possibly agevarying (non-proportional), and there is multiplicative frailty with arbitrary distribution. Our framework incorporates a wide variety of order restrictions on covariate dependence and duration dependence (ageing). We propose estimation and evaluation of age-varying covariate e¤ects when covariate dependence is monotone rather than proportional. In particular, we consider situations where the lifetime conditional on a higher value of the covariate ages faster or slower than that conditional on a lower value; this kind of situation is common in applications. In addition, there may be restrictions on the nature of ageing. For example, relevant theory may suggest that the baseline hazard function decreases with age. The proposed framework enables evaluation of order restrictions in the nature of both covariate and duration dependence as well as estimation of...

There are few studies on unemployment duration in developing countries. This is the first study on duration aspect of unemployment in Turkey. We use the results of the Household Labor Force Surveys of 2000 and 2001 to construct a cross-section of durations of unemployment spells. We analyze the determinants of probability of leaving unemployment or the hazard rate. The effects of the personal and household characteristics and the local labor market conditions are examined. Non-Parametric and parametric estimation methods are used, controlling for the unobserved heterogeneity. Two alternative definitions of unemployment are considered. The analyses are carried out for men and women separately. Our results indicate that women are experiencing higher unemployment durations then men. Age has a negative and education has a positive effect on the hazard rate. The effect of the local unemployment rate is large and negative. Duration dependence of the exit rate from unemployment is differen...

This paper considers the estimation of discrete time duration models. We highlight the enhance identification opportunities embedded in multiple spell data to separately identify the effect of duration dependence and individual time invariant unobserved heterogeneity. We consider two types of models: (i) random effects models specifying a mass point distribution for the unobserved heterogeneity; and (ii) fixed effects models in which the distribution of the effects is left unrestricted. The availability of multiple spell data allows us to consider this type of models, in the spirit of fixed effects discrete choice panel data models. We study the finite sample properties of different estimators for previous models by means of Monte Carlo simulations. Finally, as an empirical illustration, we estimate unemployment duration models using Spanish administrative data with information on the entire labor history of the individuals.

We consider the problem of planning in domains with continuous linear numeric change. Such change cannot always be adequately modelled by discretisation and is a key facet of many interesting problems. We show how a forward-chaining temporal planner can be extended to reason with actions with continuous linear effects. We extend a temporal planner to handle numeric values using linear programming. We show how linear continuous change can be integrated into the same linear program and we discuss how a ...

This paper uses an unbalanced panel dataset to evaluate how repeated job search services (JSS) and personal characteristics affect the employment rate of the prime-age female welfare recipients in the State of Washington. We propose a transition probability model to take ...

This paper studies the role played by several financial and economic indicators in determining the process of bank failure in Argentina after the Mexican crisis known as the “tequila effect”. Due to the relative scarcity of previous studies, this paper priorizes the use of semiparametric and non-parametric methods which allow us to measure the effect of explanatory variables in the process of bank failure together with duration dependence effects. The dynamic of bank failures can be fairly characterized by observable factors, which discards the possibility that it had been governed by contagion processes solely. The non-monotonocity of the implicit hazard rate suggests that there were contagion effects, and that they had a strong influence in the first 200 days of the crisis.

Standard search theory assumes that searchers are perfectly informed about their own abilities, and thus their objective chances of success in search. In contrast, we hypothesize that searchers are typically uncertain about themselves, and that this helps explain various important regularities in observed search behavior. This paper develops a general equilibrium model of the labor market in which workers are as- sumed to be uncertain about their own abilities, and to update their beliefs downward as the duration of unsuccessful search lengthens. These beliefs determine, in turn, whether an individual continues searching or not. Given suciently low beliefs about job-finding chances, search is no longer worthwhile. Importantly, beliefs need not converge to the truth in the short run: workers may search too long due to unreal- istic priors or may become overly discouraged and stop search too early. Job-finding probabilities, wages, and unemployment are determined endogenously in equil...

ABSTRACT A recent study has shown that the process of self-discharge is determined by a number of parameters such as initial voltage, temperature, and charge duration. Depending on these parameters we observed a voltage decay of 5–15% within 48h after charging. These observations hardly affect dynamic operations for supercapacitors, but have major implications for all static setups. A complex electrical model has been established to account for the redistribution effects of ions occurring in supercapacitors. Intense experimental studies suggest that these redistribution effects are in part responsible for the measured potential decays. Extended charging allows the ions to allocate themselves more homogeneously throughout the pores and therefore the voltage decay during the rest period following the charging is greatly reduced. The introduced model is capable of predicting the effects of charge duration, initial voltage, and temperature on the open circuit voltage decay.

We propose Bayesian inference in hazard regression models where the baseline hazard is unknown, covariate effects are possibly age-varying (non-proportional), and there is multiplicative frailty with arbitrary distribution. Our framework incorporates a wide variety of order restrictions on covariate dependence and duration dependence (ageing). We propose estimation and evaluation of age-varying covariate effects when covariate dependence is monotone rather than proportional. In particular, we consider situations where the lifetime conditional on a higher value of the covariate ages faster or slower than that conditional on a lower value; this kind of situation is common in applications. In addition, there may be restrictions on the nature of ageing. For example, relevant theory may suggest that the baseline hazard function decreases with age. The proposed framework enables evaluation of order restrictions in the nature of both covariate and duration dependence as well as estimation ...

This paper studies the role played by several bank specific financial indicators in determining the process of bank failure in Argentina after the Mexican crisis known as the "tequila effect". Due to the relative scarcity of previous studies, this paper priorizes the use of semiparametric and non-parametric methods which allow us to measure the effect of bank specific financial explanatory variables in the process of bank failure together with duration dependence effects without the need of arbitrary and possibly unrealistic assumptions. The dynamic of bank failures can be fairly characterized by observable factors, which discards the possibility that it had been governed by contagion processes solely. The non-monotonocity of the implicit hazard rate suggests that there were contagion effects, and that they had a strong influence in the first 200 days of the crisis.

Respiratory illness is recognized internationally as one of the commonest medical disorders affecting the world's populous countries. The identification of continuous abnormal lung sounds, like adventitious breath sounds in the total breathing cycle is of great importance in the diagnosis of obstructive airways pathologies. To this vein, the current work introduces an efficient method for the detection of wheezes, crackles,