Mosaic Research · St. Louis & St. Charles Counties
Odds at a glance
Each group's rate is the share that went on to sell. Its baseline is a home picked at random over the same window: six months for probate, about 90 days for pre-probate.
Probate
| Record | St. Louis County | St. Charles County |
|---|---|---|
| Fast filingFiled within three months of the death. | about 12% 11.0 to 13.9 · above baseline | about 19% 15.6 to 22.5 · above baseline |
| StandardFiled three to twelve months after the death. | about 9% 7.6 to 9.9 · above baseline | about 15% 12.4 to 18.9 · above baseline |
| FlaggedFiled more than a year after the death. We expect these not to sell. | about 3.5% 2.5 to 4.9 · no clear difference | about 6% 3.3 to 10.9 · above baseline |
| Baseline sale rateSix monthsA home picked at random. | 2.8% in six months 2.6 to 3.0 · random sample | 2.6% in six months every home in the county |
Sold within six months of the filing. Under each rate: its 95 percent range.
Pre-probate
| Record | St. Louis County | St. Charles County |
|---|---|---|
| Pre-probateA death on record, no probate case yet. One rate for the group. | 6% 4.0 to 9.0 · above baseline | 4.0% 2.0 to 7.7 · above baseline |
| Baseline sale rate90 days (St. Louis: 86)A home picked at random, same window. | 1.7% in 86 days every home in the county | 1.4% in 90 days every home in the county |
St. Charles County: sold within 90 days of the death. St. Louis County: changed owner between July 8 and October 2, 2026 (86 days), and its baseline counts the same thing over the same days. Not comparable with the six-month probate table.
What these rates are
- Rates for groups of records, never a promise about one house. Most houses in even the best group do not sell inside the window.
- Each rate shows the 95 percent range it was measured within. A range that includes the baseline sale rate means the group may not differ from a home picked at random at all. We show those rates anyway.
- The baseline sale rate is a home picked at random in the same county, over the same length of time as the rate it sits beside. It is not matched to the group on price, years owned, age or area, because every one of those is a choice. In St. Charles County it is every single-family home in the county (118,395 homes). In St. Louis County the probate baseline is a random sample (2,804 homes), drawn from homes our sales scrapes had not yet visited, so it may understate the county rate slightly; the pre-probate baseline is every single-family home on the county's owner roll (324,717 homes).
- Each rate carries the date it was measured through and the date it is re-measured. Probate grades: through August 2, 2026, valid until March 29, 2027. Pre-probate, St. Louis County: through October 2, 2026, valid until April 2, 2027. Pre-probate, St. Charles County: through August 2, 2026, valid until April 2, 2027. Probate baseline sale rates: through May 30, 2026, valid until March 29, 2027. Pre-probate baselines: St. Charles County through May 30, 2026, St. Louis County through October 2, 2026, both valid until April 2, 2027.
- A sale is a recorded sale of $10,000 or more, in probate, in St. Charles County pre-probate and in their baselines. St. Louis County pre-probate and its baseline count any change of owner, sale or not, so both run at or above what a sale rate would be.
The method, including the reasons for selling that did not hold up when measured, is in the calibrated odds report. Why the timing matters is in the pre-probate and probate timeframes research. Prices are on the menu.