The paper empirically studies whether pharmaceutical firms uses advertising as a signal for high quality drugs. A nested random effects count data hurdle model is introduced to handle the excess number of zero observations in the sample as well as nested random drug, firm and substance specific...

The integer-valued moving average model is advanced to model the number of transactions in intra-day data of stocks. The conditional mean and variance properties are discussed and model extensions to include, e.g., explanatory variables are offered. Least squares and generalized method of moment...

A bivariate integer-valued moving average (BINMA) model is proposed. The BINMA model allows for both positive and negative correlation between the counts. This model can be seen as an inverse of the conditional duration model in the sense that short durations in a time interval correspond to a...

This paper investigates the effects of reducing subsidies for private health insurance on public sector expenditure for hospital care. An econometric framework using simultaneous equation models is developed to analyse the interrelated decisions on the intensity and type of health care use and...

The zero inflated Poisson regression model is very common when analysing economic data that comes in the form of non-negative integers since it accounts for excess zeros and over-dispersion of the dependent variable. This model may be used in innovation analysis to see for example the impact on...

We examine properties of estimators of count data model with endogenous switching. The estimation of the count data model that accommodates endogenous switching can be accomplished by full information maximum likelihood (FIML). However, FIML estimation requires fully and correctly specified...

This article considers modeling response bias when the response is a count. The authors adopt a “structural approach†by using a generalized negative binomial mixture of Poisson distribution to model misreported counts, assuming that the distribution of the true response follows a...

In this paper we investigate the pattern of R&D efficiency in terms of the number of product innovations achieved by firms over time. Embodied in the R&D capital stock, we distinguish among physical R&D capital and human R&D capital, and allow the latter to be subject to dynamic returns along...

In this paper we analyse the role of learning through experience in Research and Development (R&D) activities in strengthening firms’ capabilities to achieve innovation outcomes. Using a production function approach, we estimate a count-data model using a panel dataset of Spanish manufacturing...

To test for group differences in growth trajectories in mixed (fixed and random effects) models, researchers frequently interpret the coefficient of Group-by-Time product terms. While this practice is straightforward in linear mixed models, it is less so in generalized linear mixed models. Using...