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 = 0.44 PLAUSIBLE as of 2026-05-01
toward the strained side: above ~62% 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 335.10 · low 63.73 · now 335.10 · 4 recessions shaded 2026
MORTGAGE30US
1971
high 18.53 · low 2.66 · now 6.66 · 7 recessions shaded 2026
How it is scored
Correlation today (r)
0.2525
z vs. its own history
0.44 on the Fisher-transformed (arctanh) correlation (effective N ≈ 27.4 independent windows, from 449 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.