  We complement a recent ApJ Letter by Luo et al. by comparing the fraction of
starburst galaxies which are interacting with the overall fraction of
interacting galaxies in the nearby galaxy population (within 40 Mpc). We
confirm that in starburst galaxies the fraction of interacting galaxies is
enhanced, by a factor of around 2, but crucially we do so by studying a sample
of almost 1500 of the nearest galaxies, including many dwarfs and irregulars.
We discuss how adjusting the starburst definition influences the final result
and conclude that our result is stable. We find significantly lower fractions
of interacting galaxies than Luo et al. did from their larger but more distant
sample of galaxies, and argue that the difference is most likely due to various
biases in the sample selection, with a representative sample of the nearest
galaxies, such as the one used here, being the best possible representation of
a general picture. Our overall conclusion is that interactions can and do
increase the number of starburst galaxies, and that this result is extremely
robust. By far most starburst galaxies, however, show no evidence of a present
interaction.
