Unweighted average labour productivities indicate an even larger German advantage over Britain than the usual employment-weighted averages. The difference between these two averages is used to compare the dispersion of productivity within 15 matched industries with positive correlations between productivity and size. In 8 of them the dispersion of productivity in Britain appears to be higher, which is consistent with a long tail of low productivity businesses vulnerable to the Single European Market. British vulnerability in the remaining 7 industries is even greater.