Carbon-ceramic vs steel brakes

A steel-braked cohort would have to be built by negation — every sale without a carbon-ceramic flag — and on this archive that is not a cohort of steel-braked cars. Only a minority of sold rows carry any option flags at all, so the rest are cars whose options were never extracted, not cars without the option. The figure that comparison would produce is a measurement of our own extraction coverage wearing a brake label.

This is not the same as a thin sample, and it is worth the distinction: a thin sample fills in as the archive grows, and this does not. It needs the extractor to record that a car does not have the option, which is a different fact from not having found that it does.

• · Gated manual vs F1 — Factory manual short by 1
• · Conversion vs factory manual — Manual conversion short by 3
• · Scuderia vs Berlinetta — published
• · 16M vs Scuderia — published

Drawn from 73 recorded sales. Medians are taken over the last twelve months and a cohort below 5 sales publishes no median at all — see prices for the whole archive.