PUZZLED AGAIN

I found this graph of (non-financial) corporate liquid assets in a post by Kevin Drum:

Kevin got the chart from Ezra Klein, who claimed that the Federal Reserve compiles this information. I went to FRB site and was pretty confused about what Kevin & Ezra were referring to until I found this interactive chart page and I selected income before taxes, gross saving less net capital transfers paid, and checkable deposits and currency:

I was puzzled because I thought "liquid assets" meant "cash" but that's not the case here. Instead, it means assets that can fairly easily be converted to cash.

Not also that this "cash hoarding" began at about the same time (say, 1970), that the Establishment had become terrified of the Dirty Hippies.