When mortgage rates rise, home prices should soften — financing is the binding constraint on what buyers can pay. Prices climbing WHILE rates climb is affordability decoupling from the cost of money.
BEHAVING z = 0.53 PLAUSIBLE as of 2026-03-01
toward the strained side — above ~66% of its history
The dysfunction statistic, full history
Above the dashed zero line is the economically wrong direction — the
relationship failing to do its stabilizing job.
The two series it watches
CSUSHPINSA
1987
high 331.61 · low 63.73 · now 329.94 · 4 recessions shaded 2026
MORTGAGE30US
1971
high 18.53 · low 2.66 · now 6.48 · 7 recessions shaded 2026
How it is scored
Correlation today (r)
0.2734
z vs. its own history
0.53 on the Fisher-transformed (arctanh) correlation — effective N ≈ 27.3 independent windows (from 447 overlapping readings)
Rule, pre-committed
z < 1 BEHAVING · 1 ≤ z < 2 STRAINED · z ≥ 2 with the wrong economic sign, held 3 consecutive readings, DECOUPLED.
Confidence
PLAUSIBLE — Rolling 24-month correlation of monthly Case-Shiller price changes and changes in the 30y fixed rate; the lag from rate to price is real, so read the persistence, not a single month.