A while ago we had an excellent talk at County Hall Dorchester by Dr Sam
Moorhead from the PAS on coin find statistics. Some detectorists were in
the audient and in the Q&A at the end, Dr Moorhead asked what proportion
of finds were reported? The guesstimate was 25%.
And it emerged there was a skew - detectorists are more interested in
gold and silver coins, but the archaeologist likes anything datable so
even collaborating, honest detectorists under-report archaeologically