BIDA has now finished its second year alternating between mask-optional and mask-required dances. What effect does this have on attendance?

I tried to look at this in January 2024, but with only eleven dances it was hard to say. Now that we have four times as many, we can get a better sense:

This is only regular dances, no special events. So no family dances, double dances, or Elixir's last dance (which had a session of couples dancing).

Overall, the mask-required dances averaged 166 people (median 160) while the mask-optional dances averaged 190 (median 184).

This is consistent with the survey results: 23% of respondents reported attending every time, rising to 35% in a hypothetical where the dance stopped ever requiring masks. Similarly, 67% reported attending at least monthly, falling to 58% in a hypothetical where the dance started always required masks.

Total attendance is not the only thing that matters, though, and one important benefit of holding both categories of dance is that people who are only willing to come to mask required or mask optional dances can do that.