Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We extend the simulation results in Santos Silva and Tenreyro (2006, The log of gravity, The Review of Economics and Statistics, 88, 641-658) by considering a novel data-generating process. Our results confirm that the Poisson pseudo-maximum likelihood estimator is generally well behaved, even when the proportion of zeros in the sample is very large.