[Alberta's Child]

What causes a negative interest rate, then?

The best evidence that we had of a serious deflationary problem was the ripple of mortgage defaults after 2008 where banks didn't even foreclose on the mortgages because they didn't want to take possession of an asset that was declining in value. This is a classic case of a deflationary spiral setting in.

[Garth Tater]

What causes a negative interest rate, then?

I beat you by a minute there :)

See my post #51 (hint, it is not a deflationary environment)