The statistics collector documentation says:
"The parameter stats_start_collector
s.html#GUC-STATS-START-COLLECTOR> must be set to true for the
statistics collector to be launched at all. This is the default and
recommended setting, but it may be turned off if you have no interest in
statistics and want to squeeze out every last drop of overhead. (The
savings is likely to be small, however.) Note that this option cannot be
changed while the server is running. "
Is there a way to quantify what 'likely to be small' is?