Van Dijk et al. found different results for some variables explaining the large/small firm innovation advantage in a number of Acs and Audretsch publications. Their own research adds to this variety. However, the differences van Dijk er al. found between the Acs and Audretsch studies can be largely attributed to specification and sample differences. The same applies to the observed differences between Acs and Audretsch and van Dijk et al.