In our last column we talked about the economic effectiveness (keizai kōka) of the 2020 Tokyo Olympics. Keizai kōka is often used as an indication of how much money a given scheme or phenomenon adds to a particular economy. As we pointed out, the number only takes into consideration the positive effects of the phenomenon or scheme, and in that regard it's interesting to look at one that has received a good deal of attention lately because of how clearly it illustrates the growth of a certain phenomenon: namely, the market surrounding cats, or, what professor Kasuhiro Miyamoto of Kansai University has dubbed "nekonomics," or the "economics of cats."