Economist Jason abeluck conducted a study in rural Bangladesh. He randomized hundreds of villages to three different strategies, no masking, cloth masking, or a sur a masks. In the villages that he gave a mask out, about ten % more people signed up to participate than the villages where he didn't give a mask out. That's a statistically significant ten per cent im balance. And i think the answer is that when they went to randomize people, the villagers knew that they were going to get a free bee.