Exceptions were that the late respondents were a
little older, held more senior level positions, and fewer
of them came from the medium size accounting firms.
When using another method comparing the means for
participants who responded within 20 days (therefore
around the time the second reminder was sent) of the
survey start date in the province, and for those who
responded afterwards, two of the significant differences
identified above disappeared, leaving only the medium
size accounting firm variable as significant. This seems
to suggest that there is unlikely to be serious systematic
bias due to non-response, especially if the non-response
group is compared with the larger sample rather than
just those who responded promptly.