Negative rates (Theoretically) essentially force investors to move capital into greater yielding investments - buy businesses, buy stocks, invest in business infrastructure...
It did trickled down: https://www.cnbc.com/2019/08/12/dan...r-mortgages-with-negative-interest-rates.html I am waiting for this to happen in the US. Trump would love it, all homeowners would love it.
mortgage rates would actually go up as there is risk of mortgage default as jobs are harder to get. People who get laid off may not able to find jobs. or banks want higher downpayment Instead of 10% downpayment, you'll need like 30% downpayment and higher mortgage qualifications. if homes are less liquid. Mortgage rates won't get negative rates as they are not traded. You might get negative rates in 'trading' these bonds in the illiquid manipulated electronic markets but not in the real world.