Search results for "logit"

Testing for Asymmetric Information in Insurance Markets: A Multivariate Ordered Regression Approach

2018

The positive correlation (PC) test is the standard procedure used in the empirical literature to detect the existence of asymmetric information in insurance markets. This article describes a new tool to implement an extension of the PC test based on a new family of regression models, the multivariate ordered logit, designed to study how the joint distribution of two or more ordered response variables depends on exogenous covariates. We present an application of our proposed extension of the PC test to the Medigap health insurance market in the United States. Results reveal that the risk–coverage association is not homogeneous across coverage and risk categories, and depends on individual so…

Accounting for Interdependent Risks in Vulnerability Assessment of Refugees

2020

The United Nations’ Vulnerability Assessment Framework (VAF) of refugees encompasses a set of indicators of the living conditions in refugee camps in Lebanon and Jordan; it assumes the independence among its components. In this paper we maintain the importance to account for existing interdependencies, and provide a definition of vulnerability for high income countries. The proposed “vulnerability scale”, based on the estimated joint risk of social isolation, economic deprivation and bad health, is a useful tool to address interventions toward selected groups of more vulnerable refugees. Analyses are based upon the survey of refugees carried on in Germany in 2016. Germany is the first count…

L'effetto di Montalbano sui flussi turistici nei luoghi letterari e televisivi

2015

Da alcuni anni vari enti regionali erogano a fondo perduto a favore di produzioni cinematografiche o televisive nei loro territori, talvolta attraverso le c.d. Film Commission. Di solito cio viene giustificato dall’impatto occupazionale delle riprese e da quello indotto sul cine-turismo. Obiettivo di questo saggio e misurare l’impatto dei telefilm sui flussi turistici delle localita dove essi sono stati girati, al fine di valutare se tali erogazioni a fondo perduto siano opportune; cio attraverso un’indagine empirica (nel periodo 1982-2013) sull’incremento turistico indotto dalle serie TV con il commissario Montalbano. Confrontando gli arrivi nella provincia di Ragusa, sede delle riprese te…

Design and analysis of discrete choice experiments for models with response time

2013

Luminescence activity of irradiated SiO2-clathrate Melanophlogite

2013

What keeps young adults in permanent poverty? A comparative analysis using ECHP

2009

Abstract Previous studies suggest that there are strong differences in the rates of youth poverty across European countries. Rather surprisingly, it is found to be high in Scandinavian countries, and relatively speaking, lower in Mediterranean and Anglo-Saxon countries. This somewhat unexpected finding prompts the question whether the incidence of poverty is an appropriate measure of youth disadvantage. Instead of considering poverty rates we consider the length of recorded poverty spells, taking into account explicitly the temporal sequencing of the episodes of poverty. Using the European Community Household Panel, individuals are classified into different groups of poverty permanence, eac…

Modeling the coupled return-spread high frequency dynamics of large tick assets

2015

Large tick assets, i.e. assets where one tick movement is a significant fraction of the price and bid-ask spread is almost always equal to one tick, display a dynamics in which price changes and spread are strongly coupled. We introduce a Markov-switching modeling approach for price change, where the latent Markov process is the transition between spreads. We then use a finite Markov mixture of logit regressions on past squared returns to describe the dependence of the probability of price changes. The model can thus be seen as a Double Chain Markov Model. We show that the model describes the shape of return distribution at different time aggregations, volatility clustering, and the anomalo…

Bayesian joint ordinal and survival modeling for breast cancer risk assessment

2016

We propose a joint model to analyze the structure and intensity of the association between longitudinal measurements of an ordinal marker and time to a relevant event. The longitudinal process is defined in terms of a proportional-odds cumulative logit model. Time-to-event is modeled through a left-truncated proportionalhazards model, which incorporates information of the longitudinal marker as well as baseline covariates. Both longitudinal and survival processes are connected by means of a common vector of random effects. General inferences are discussed under the Bayesian approach and include the posterior distribution of the probabilities associated to each longitudinal category and the …

Centile estimation for a proportion response variable

2015

This paper introduces two general models for computing centiles when the response variable Y can take values between 0 and 1, inclusive of 0 or 1. The models developed are more flexible alternatives to the beta inflated distribution. The first proposed model employs a flexible four parameter logit skew Student t (logitSST) distribution to model the response variable Y on the unit interval (0, 1), excluding 0 and 1. This model is then extended to the inflated logitSST distribution for Y on the unit interval, including 1. The second model developed in this paper is a generalised Tobit model for Y on the unit interval, including 1. Applying these two models to (1-Y) rather than Y enables model…

Fitting generalized linear models with unspecified link function: A P-spline approach

2008

Generalized linear models (GLMs) outline a wide class of regression models where the effect of the explanatory variables on the mean of the response variable is modelled throughout the link function. The choice of the link function is typically overlooked in applications and the canonical link is commonly used. The estimation of GLMs with unspecified link function is discussed, where the linearity assumption between the link and the linear predictor is relaxed and the unspecified relationship is modelled flexibly by means of P-splines. An estimating algorithm is presented, alternating estimation of two working GLMs up to convergence. The method is applied to the analysis of quit behavior of…