To resolve an argument there’s nothing quite like Google Scholar. Should toilet seats be left up or down?
First of all a disclaimer. It might be too expensive to move from our current toilet seat norm to a different one. Expensive I mean in terms transition costs, maybe the social anxiety and anti-social behaviour required to move us would be more awful than the small benefits we gain from moving from one norm to the other. Even if that’s true, these are still interesting, and vital, matters to discuss.
What the women are dreading, and the men  are hoping for is that I’m going to say toilet seats should be left up, not down. I am not. Lots of people would like to argue that the toilet seat being one way or the other is inherently better, more hygienic or sightly but those arguments are destined to be weak. If Dr. J. Evans Pritchard can’t tell the worth of a poem toilet seats are beyond us all.
There are two things to bear in mind while norm choosing. First is the inconvenience of leaving the toilet seat other than you’d like to find it and the other is the inconvenience of finding the toilet seat other than you’d like to find it. Compared to NGDP growth shortfalls this is all unimportant, but we’re lucky enough to live in an age when we’re allowed to care about the unimportant, embrace it.
I think visually, and the below graph helped clear up my thinking on the subject, taken from the above linked paper by Jay Pil Choi.
If everyone is a woman then seat down is clearly optimal. If everyone is a man then seat up is clearly optimal. That is if we assume the inconvenience of putting up and down a toilet seat is roughly equal. A reasonable assumption, although feel free to register your complaints in the comments.
First of all, a woman having used a toilet is predictive of another woman using that toilet next. Either because the same woman will come back or because the presence of one woman is indicative of there being other women in the vicinity or using that facility in particular.
The more important and logical strand of argument is different though, when society operates under a seat up or seat down rule one set of people must incur the inconvenience of using the seat on every (for women) or almost every (for men) occasion. The other group incurs no toilet seat related inconvenience.
Because of these two interrelated the socially optimal arrangement is for you to leave the toilet seat alone. This is what the above graph shows. Only under circumstances of extreme asymmetry in terms of inconvenience does it become important whether the seat is left on way or the other.
This finding is trivial, but also profound.
First of all because it shows that being selfish is good. The world is a better place because of selfishness as selfishness. Adam Smith argued that the selfish interest of the butcher and baker helped provide us with a service, when it comes to toilet seats there are direct positive externalities from selfishness.
Secondly, the results are generalisable. More things in life are like toilet seats than you realise.  When sharing a car, leaving it as you want it is superior to always returning it to someone else’s preference, or to somewhere neutral.
A society which is more selfish, and more accepting of bring selfish, does not therefore represent a move towards barbarism, but represents a sort of progress. Thing of that next time you’re on the toilet. In fact, some of you may be there right now reading this on your phone. Take my advice. Leave the seat alone and go and do something you enjoy.
 Yep, just thought, “that’s very cissexist of you”, but sod it, I’m talking about toilet seats. 
 What do you mean you come here for serious political analysis? You really haven’t been paying attention these last four years.