An example is the adoption of the internet as a means of communication. To correct for these biases time fixed effects are introduced under the assumption that the source for unobserved heterogeneity does not vary across countries. They propose the use of a dynamic specification using a Least Squares Dummy Variable Corrected (LSDVC) estimator to account for this. Additionally complications in the estimation can also arise from the truncated nature of the dependent variable. The Gini coefficient which is used as dependent variable lies in the 0-1 interval and this may require the use of a logistic estimation.