The author neglects to include the cause for yelling, which is the occasional but extremely large cost to Marsha and John of falling into the toilet when sitting while the seat is up. Assuming #1 alone or #1 and #2 together occur at 3xfrequency of #2 alone, Marsha runs this risk 3x more than John. The author also neglects the cost to John of sitting for #1 and thus eliminating the whole problem of toilet seat position. I argue the cost is 0 considering John sits for #2 in any case, unless John is John Holmes. This strategy has the additional benefit of increased cleanliness/decreased pee on outside of bowl, wall and floor for whoever cleans the bathroom, which is statistically more likely to be Marsha. Therefore standing for #1 incurs a cost for (most likely) Marsha.