US pet food total market sales

Between 2014 and 2022, Japan's population declined while US pet food sales increased, producing an inverse correlation of -0.9632 across nine data points. The theory that Japan's population is being converted into American pet food is horrifying, impossible, and exactly the kind of thing that a correlation coefficient cannot rule out. What the data actually describes is two independent demographic phenomena: a country that is shrinking because its people aren't having children, and a country that is spending more on animals because it is treating them like children. Both trends are about the same thing, in a way: what happens when advanced societies redirect their nurturing instincts.

Japan's population declined from 127 million to under 125 million due to sub-replacement fertility and limited immigration. US pet food sales grew from $24 billion to over $42 billion, driven by pet humanization and premium products. Both are demographic-adjacent trends moving in opposite directions—one measuring population contraction, the other measuring the economic consequences of pet-as-family-member culture.

A declining population in one country and growing pet spending in another will produce an inverse correlation when they share a time window. The data accidentally describes two developed nations' different responses to the same underlying phenomenon: changing family structures.