I'm actually more persuaded by the theory of universal displacement because at some point you have to reach saturation, where each person who wants another teaspoon at home has sufficient teaspoons. Could a follow up study please address worker turnover, visitor amounts and how many teaspoons does the average man need anyway? Actually it almost looks like a population graph in the programme-linked tearoom, where people believe there to be a minimum level of teaspoons required and anything above that is subject to being picked off. I believe with reintroduction of teaspoons, including teaspoon mating programs the graph would reflect a hunter-prey relationship between man and teaspoon. Of course that isn't applicable for communal tearooms, where people just take anything that isn't nailed to the ground. Edit: This has prompted more discussion in my household. Does the theft move onto forks and then knives? Forks can still be used as a teagbag extraction implement (TEI), but knives are substantially trickier.