> Per the US government, which tracks what people in different deciles actually spend on various things in surprising detail, the median US household has ~$1,000 in cash left over every month after all ordinary expenditures.

I'm really not trying to be the "citation needed" dick, but I would genuinely love to look at the source for this. What I found from googling was a hodgepodge of unreliable information, or studies that are decades old.

EDIT - just went straight to the source, since articles linking the source couldn't find it.

https://www.bls.gov/cex/tables/calendar-year/mean-item-share...

It roughly lines up, although it seems to be trending down recently.