A dramatically large number of corner solutions occur when estimating by (Gaussian) maximum likelihood a simple model for panel data with random effects and autocorrelated errors. This can invalidate results of applications to panel data with a short time dimension, even in a correctly specified...

Within the framework of dynamic panel data models with mean stationarity, one additional moment condition may remarkably increase the efficiency of the system GMM estimator. This additional condition is essentially a condition of “homoskesdasticity” of the individual effects; it is...

This paper develops a new moment condition for estimation of linear panel data models. When added to the set of instruments devised by Anderson, Hsiao (1981, 1982) for the dynamic model, the proposed approach can outperform the GMM methods customarily employed for estimation. The proposal builds...

The estimation of limited dependent variable panel data models usually involves objective functions in which integrals appear without a closed form solution: this is the case of the panel data Tobit model with random effects. Recently, simulation methods have shown to be useful in the inference...

This paper aims at characterizing the dynamics of R&D competition within the pharmaceutical domain, focusing on the role of patent disclosure, the extent of uncertainty, and role of scientific advances. Following the empirical literature in the economics of innovation, we employ patents as a...

During the last thirty years health care expenditure (HCE) has been growing much more rapidly than GDP in all OECD countries posing increasing concern on the long-term sustainability of current trends. Against this background, we look at the determinants of HCE in European countries, explicitly...

We analyze the decline of R&D productivity in pharmaceuticals and its determinants. Since the molecular biology revolution, science has dramatically expanded the set of plausible therapeutic targets. However, innovation has become more difficult to achieve, and attrition rates of R&D projects...