Thanks Jess, that is a more detailed overview, but the point still stands. Paying off your mortgage in 15 years (or less) rather than 30 is in itself advice to put additional money to pay down the mortgage.

Since our pay check is a zero sum game, paying down the mortgage in half the time by definition means we have less money to invest. So the question becomes, is that good advice? My thought is that if your mortgage rate is low (below 4%) and you have room to invest in tax sheltered accounts, then No it’s not optimal.

If you refinance and mortgage rates rise to 4% or above, then it starts to make sense