86,309 research outputs found
A model with simultaneous first and second order phase transitions
We introduce a two dimensional nonlinear XY model with a second order phase
transition driven by spin waves, together with a first order phase transition
in the bond variables between two bond ordered phases, one with local
ferromagnetic order and another with local antiferromagnetic order. We also
prove that at the transition temperature the bond-ordered phases coexist with a
disordered phase as predicted by Domany, Schick and Swendsen. This last result
generalizes the result of Shlosman and van Enter (cond-mat/0205455). We argue
that these phenomena are quite general and should occur for a large class of
potentials.Comment: 7 pages, 7 figures using pstricks and pst-coi
Non-pecuniary returns to higher education: the effect on smoking intensity in the UK
This paper investigates whether higher education (HE) produces non-pecuniary returns via a reduction in the
intensity of consumption of health-damaging substances. In particular, it focuses on current smoking intensity of the British individuals sampled in the 29-year follow-up survey of the 1970 British Cohort Study. We estimate endogenous dummy ordinal response models for cigarette consumption and show that HE is endogenous with respect to smoking intensity and that even when endogeneity is accounted for, HE is found to have a strong negative effect on smoking intensity. Moreover, pecuniary channels, such as occupation and income, mediate only a minor part of the effect of HE. Our results are robust to modelling individual self-selection into current smoking
participation (at age 29) and to estimating a dynamic model in which past smoking levels affect current smoking levels
The Determinants of Immigration-Policy Preferences in Advanced Economies: A Cross-Country Study
This paper employs survey data to examine the determinants of immigration-policy preferences among ten advanced economies. Ordered probit specifications suggest that skill level is a robust determinant of immigration-policy preferences and that less-skilled workers are more likely to express a preference for policies that restrict immigration. The results also suggest that older individuals, members of trade unions, and those who classify their political ideology as conservative are more likely to favor limiting immigration while non-citizens are less likely to favor such policies. Individual country-level regression results vary, in particular with regard to the influence of trade union member- ship, which is a robust determinant of immigration-policy preferences for both measures of skill in only a subset of nations. (JEL FO, F2, HO
Model-based approach for household clustering with mixed scale variables
The Ministry of Social Development in Mexico is in charge of creating and assigning social programmes targeting specific needs in the population for the improvement of the quality of life. To better target the social programmes, the Ministry is aimed to find clusters of households with the same needs based on demographic characteristics as well as poverty conditions of the household. Available data consists of continuous, ordinal, and nominal variables, all of which come from a non-i.i.d complex design survey sample. We propose a Bayesian nonparametric mixture model that jointly models a set of latent variables, as in an underlying variable response approach, associated to the observed mixed scale data and accommodates for the different sampling probabilities. The performance of the model is assessed via simulated data. A full analysis of socio-economic conditions in households in the Mexican State of Mexico is presented
Determinants and Consequences of Bargaining Power in Households
A growing literature offers indirect evidence that the distribution of bargaining power within a household influences decisions made by the household. The indirect evidence links household outcomes to variables that are assumed to influence the distribution of power within the household. In this paper, we have data on whether a husband or wife in the Health and Retirement Study %u201Chas the final say%u201D when making major decisions in a household. We use this variable to analyze determinants and some consequences of bargaining power. Our analysis overcomes endogeneity problems arising in many earlier studies and constitutes a missing link confirming the importance of household bargaining models. We find that decision-making power depends on plausible individual variables and also influences important household outcomes, with the second set of results much stronger than the first set. Current and lifetime earnings have significant but moderate effects on decision-making power. On the other hand, decision-making power has important effects on financial decisions like stock market investment and total wealth accumulation and may help explain, for example, the relatively high poverty rate among widows.
New goodness-of-fit diagnostics for conditional discrete response models
This paper proposes new specification tests for conditional models with
discrete responses, which are key to apply efficient maximum likelihood
methods, to obtain consistent estimates of partial effects and to get
appropriate predictions of the probability of future events. In particular, we
test the static and dynamic ordered choice model specifications and can cover
infinite support distributions for e.g. count data. The traditional approach
for specification testing of discrete response models is based on probability
integral transforms of a jittered discrete data which leads to continuous
uniform iid series under the true conditional distribution. Then, standard
specification testing techniques for continuous variables could be applied to
the transformed series, but the extra randomness from jitters affects the power
properties of these methods. We investigate in this paper an alternative
transformation based only on original discrete data that avoids any
randomization. We analyze the asymptotic properties of goodness-of-fit tests
based on this new transformation and explore the properties in finite samples
of a bootstrap algorithm to approximate the critical values of test statistics
which are model and parameter dependent. We show analytically and in
simulations that our approach dominates the methods based on randomization in
terms of power. We apply the new tests to models of the monetary policy
conducted by the Federal Reserve
Modeling migraine severity with autoregressive ordered probit models
This paper considers the problem of modeling migraine severity assessments and their dependence on weather and time characteristics. Since ordinal severity measurements arise from a single patient dependencies among the measurements have to be accounted for. For this the autore- gressive ordinal probit (AOP) model of MĂŒller and Czado (2004) is utilized and fitted by a grouped move multigrid Monte Carlo (GM-MGMC) Gibbs sampler. Initially, covariates are selected using proportional odds models ignoring this dependency. Model fit and model comparison are discussed. The analysis shows that humidity, windchill, sunshine length and pressure differences have an effect in addition to a high dependence on previous measurements. A comparison with proportional odds specifications shows that the AOP models are preferred
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