“He calculated that to make the incremental costs to the man and the woman roughly equal, the woman should always leave the seat down when she’s finished, and the man should put it back down half of the time after he pees.
This assumes that he poops on about a third of his bathroom visits, though, which seems a little high. If the real number is a bit lower, then he’ll have to lower the seat after peeing somewhat more often — perhaps two thirds of the time.
Of course, these calculations assume there’s an equal number of men and women using the toilet. If there are more of one or the other, it’d skew things slightly — making it so that the men should raise or lower the seat more often, respectively.”