10,418 research outputs found

    A computationally practical simulation estimation algorithm for dynamic panel data models with unobserved endogenous state variables

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    This paper develops a new simulation estimation algorithm that is particularly useful for estimating dynamic panel data models with unobserved endogenous state variables. The new approach can deal with the commonly encountered and widely discussed ``initial conditions problem,'' as well as the more general problem of missing state variables at any point during the sample period. Repeated sampling experiments on a dynamic panel data probit model with serially correlated errors indicate that the estimator has good small sample properties and is computationally practical for use with panels of the size that are likely to be encountered in practice. <br><br> Keywords; initial conditions, missing data, discrete choice, simulation estimation

    A Computationally Practical Simulation Estimation Algorithm for Dynamic Panel Data Models with Unobserved Endogenous State Variables

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    This paper develops a simulation estimation algorithm that is particularly useful for estimating dynamic panel data models with unobserved endogenous state variables. The new approach can easily deal with the commonly encountered and widely discussed “initial conditions problem,” as well as the more general problem of missing state variables during the sample period. Repeated sampling experiments on dynamic probit models with serially correlated errors indicate that the estimator has good small sample properties. We apply the estimator to a model of married women’s labor force participation decisions. The results show that the rarely used Polya model, which is very difficult to estimate given missing data problems, fits the data substantially better than the popular Markov model. The Polya model implies far less state dependence in employment status than the Markov model. It also implies that observed heterogeneity in education, young children and husband income are much more important determinants of participation, while race is much less important.Initial Conditions, Missing Data, Simulation, Female Labor Force Participation Decisions

    Relativistic corrections of one-nucleon current in low-energy three-nucleon photonuclear reactions

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    Proton-deuteron radiative capture and two- and three-body photodisintegration of 3He at low energy are described using realistic hadronic dynamics and including the Coulomb force. The sensitivity of the observables to the relativistic corrections of one-nucleon electromagnetic current operator is studied. Significant effects of the relativistic spin-orbit charge are found for the vector analyzing powers in the proton-deuteron radiative capture and for the beam-target parallel-antiparallel spin asymmetry in the three-body photodisintegration of 3He.Comment: 7 figures, accepted for publication in Phys. Rev.

    Meson and Quark Degrees of Freedom and the Radius of the Deuteron

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    The existing experimental data for the deuteron charge radius are discussed. The data of elastic electron scattering are inconsistent with the value obtained in a recent atomic physics experiment. Theoretical predictions based on a nonrelativistic description of the deuteron with realistic nucleon-nucleon potentials and with a rather complete set of meson-exchange contributions to the charge operator are presented. Corrections arising from the quark-gluon substructure of the nucleon are explored in a nonrelativistic quark model; the quark-gluon corrections, not accounted for by meson exchange, are small. Our prediction for the deuteron charge radius favors the value of a recent atomic physics experiment.Comment: 20 pages, LaTeX, 4 Postscript figures, to appear in Few-Body-System

    A Computationally Practical Simulation Estimation Algorithm for Dynamic Panel Data Models with Unobserved Endogenous State Variables

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    This paper develops a simulation estimation algorithm that is particularly useful for estimating dynamic panel data models with unobserved endogenous state variables. The new approach can easily deal with the commonly encountered and widely discussed "initial conditions problem," as well as the more general problem of missing state variables during the sample period. Repeated sampling experiments on dynamic probit models with serially correlated errors indicate that the estimator has good small sample properties. We apply the estimator to a model of married women's labor force participation decisions. The results show that the rarely used Polya model, which is very difficult to estimate given missing data problems, fits the data substantially better than the popular Markov model. The Polya model implies far less state dependence in employment status than the Markov model. It also implies that observed heterogeneity in education, young children and husband income are much more important determinants of participation, while race is much less important.simulation, missing data, initial conditions, female labor force participation

    The Subcolonization and Buildup of \u3ci\u3eTetrastichus Julis,\u3c/i\u3e (Hymenoptera: Eulophidae) a Larval Parasitoid of the Cereal Leaf Beetle, (Coleoptera: Chrysomelidae) in the Lower Peninsula of Michigan

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    Following initial establishment of the parasitoid, Tetrastichus julis (Walker), at a carefully managed field nursery, releases of parasitized Oulema melanopus larvae were made by Michigan county agents at preselected sites throughout the lower peninsula during 1970-74. A follow-up recovery program during 1971-75 revealed continued dispersion and population increase for T. julis. An independent census verified the increasing rates of parasitism

    Evaluation of anomalies observed on film from S-190A flight system calibration test

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    Due to a persistent problem of scratched film from testing of the Skylab S-190A system, a series of tests were designed to identify the cause of the film scratching. The procedures followed in this test for pretest handling and packaging of the film, the makeup of the rolls for processing, and the results of the processed film evaluation are reported

    A metafrontier approach to measuring technical efficiencies across the UK dairy sector

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    A regional approach is applied to measure technical efficiencies on dairy farms which employs the deterministic metafrontier approach. We construct six super regions for the UK, i.e. Eastern, Western, Northern England, Wales, Scotland and Northern Ireland. Data are collected through three different administrative systems, all be it under the same FADN guidance. We find for dairy farming comparative indicators of performance in all three data sets. The stochastic frontier approach is applied to construct 6 regional frontiers and a pooled (UK) dataset for comparison. A likelihood ratio test rejects the null hypothesis that these regions operate under a common frontier which may indicate bias in previous attempts to measure dairying efficiency at the country level. Mean technical efficiencies are high for the period 2005 to 2008, though there is some indication that little technical progress has occurred since decoupling of CAP payments from production in all regions. The metafrontier presents estimates against a common technology and mean scores range from below 0.50 for the English regions and Northern Ireland, 0.52 for Wales and 0.56 for Scotland. This paper promotes the application of the deterministic metafrontier approach for similar sub-country studies.Stochastic Production Frontiers, Metafrontiers, UK Farm Account Data, Dairy farming., Agricultural and Food Policy, Q12, D24, C23, C51,
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