This paper tests empirically the hypothesis that the greater the intangibility of a firm’s resources, the greater the sustainability of its competitive advantage. Resource intangibility is measured by: (1) Tobin’s q and (2) the predicted value from a hedonic regression of q on several accounting measures of intangibles. Sustainability is measured by the persistence of firm-specific profits. Usi...

Using panel data we investigate the relationship between income inequality and economic development. We employ a threshold regression model that allows for endogenous income thresholds and find strong evidence of a two-regime split in our sample.  2000 Elsevier Science S.A. All rights reserved.

We consider panel count data which are frequently obtained in prospective studies involving recurrent events that are only detected and recorded at periodic assessment times. The data take the form of counts of the cumulative number of events detected at each inspection time, along with explanatory covariates. Examples arise in diverse areas such as epidemiological studies, medical follow-up st...

In this paper we provide a new methodology to analyze the (Gaussian) profile quasi likelihood function for panel regression models with interactive fixed effects, also called factor models. The number of factors is assumed to be known. Employing the perturbation theory of linear operators, we derive a power series expansion of the likelihood function in the regression parameters. Using this exp...

This paper studies estimation and inference in a quantile regression dynamic panel model with fixed effects. Panel data fixed effects estimators are typically biased in the presence of lagged dependent variables as regressors. To reduce the dynamic bias in the quantile regression panel data model I develop an instrumental variables approach that employs lagged regressors as instruments. I show ...

This paper studies fixed effects estimation of quantile regression (QR) models with panel data. Previous studies show that there are two important difficulties with the standard QR estimation. First, the estimator can be biased because of the well-known incidental parameters problem. Secondly, the non-smoothness of the objective function significantly complicates the asymptotic analysis of the ...

In this study, we develop a novel estimation method for quantile treatment effects (QTE) under rank invariance and stationarity assumptions. Ishihara (2020 Ishihara, T. (2020), “Identification Estimation of Time-Varying Nonseparable Panel Data Models Without Stayers,” Journal Econometrics, 215, 184–208. DOI: https://doi.org/10.1016/j.jeconom.2019.08.008.[Crossref] , [Google Scholar]) explores i...