What a late delivery costs a marketplace

96,470 real orders from Olist, a Brazilian marketplace. Late orders get 2 points lower reviews on a 1-5 scale. The question is how much of that gap the delay itself causes, whether it can be seen coming at checkout, and whether it costs the customer too.

-1.97review points caused by arriving late (doubly robust)
-0.98already at 1-3 days late
23%of delays flagged in the riskiest 10% at checkout
74%of late orders reviewed before the parcel arrived

01The delay, not the order, drives the score

EstimatorEffect on review score
Naive difference-2.02
OLS with purchase-time covariates-1.98
Inverse propensity weighting-1.97
AIPW, cross-fitted LightGBM-1.97 (95% CI -2.02 to -1.93)

Adjusting for distance, states, items, price, category and purchase date barely moves the estimate. A hidden confounder would need to explain 27% of the residual variance of both lateness and score to erase it; the strongest observed one explains about 1%.

Bar chart of the effect of lateness on review score by band: about -1 for 1-3 days, -2.15 for 4-7 days, and about -2.5 for 8-14 and 15+ days, with naive and adjusted bars nearly equal.
The damage is front-loaded: one point after 1-3 days, more than two after a week, then a floor.
Histogram of cross-fitted propensity scores for on-time and late orders; both groups cover the same range, on-time orders concentrated near zero.
Late orders have on-time look-alikes across the propensity range, so the comparison does not extrapolate.

02The cleaning step that would have biased everything

Olist sends its survey when the parcel arrives or when the promised date passes. For late orders the survey usually comes first: 74% of them were reviewed before delivery, by customers who already knew. Dropping pre-delivery reviews, the obvious cleanup, would keep only a quarter of the late orders and none more than 8 days late.

03Seeing delays coming

Cumulative capture curve: share of late deliveries flagged against share of orders flagged, for orders placed April to August 2018; the model curve sits above the random diagonal, reaching about 23% at 10% and 40% at 20%.
Checkout-time model, trained to March 2018 and scored on April-August 2018: AUC 0.69. Useful as a triage list, not a guarantee; most delays come from events that do not exist at checkout.

04Does it cost the customer?

Only 3% of Olist customers ever buy again. After a late first order, 2.6% returned within 180 days against 3.1% after an on-time one, but the adjusted effect (-0.4 points, 95% CI -1.0 to +0.2) and the Cox hazard ratio (0.90, CI 0.78-1.03) cannot rule out zero. Effects under about one percentage point are beyond what this data can detect.