int_dirty_air_tax_component

One row per lap.

Part of the Physics family.

For the conceptual foundation, read Int Dirty Air Tax Component.

One row per lap. Cost of driving in dirty air (turbulent wake) following another car. Uses prior-lap dirty-air intensity to establish causality: current lap slowdown → prior lap’s position. Avoids reverse causality. Seconds lost = θ_air × dirty_air_intensity_lag1, capped [0, 5.0] seconds. θ_air IS FITTED FROM THE DATA, not configured: it is the OLS slope of partial residual on the lagged dirty-air bit over the full two-arm calibration panel (treated and untreated laps). Before 08q (2026-09-21) the panel was filtered to dirty_air_share_lag1 > 0, which left the binary regressor constant and unidentified, so θ_air silently fell through a COALESCE to the literal 0.5 s/lap on every build and dirty_air_tax_s was 0.5 on every dirty-air lap and 0.0 otherwise. Measured on the v12 substrate the fitted value is +0.1310 s/lap [95% CI +0.1144, +0.1476] over 123,993 laps — the shipped 0.5 was 3.8x too high. The COALESCE literal is now that measured estimate and serves only as a degenerate-panel guard. A global pooled θ is used deliberately; per-season θ runs +0.418 (2018) to -0.011 (2024) and is not distinguishable from zero on 2021 and 2024, which is an open ruling for any fan-facing surface that reports per-driver seconds (see work/08-foundations-repair.md section 08q).

Lineage

Overview

Property	Value
Layer	intermediate
Family	Physics
Contract enforced	No
Tags	causal_decomposition, dirty_air
Upstream	int_lap_fuel_state, int_field_pace_curve, int_stint_geometry, int_lap_air_state, int_event_corrections, int_track_evolution

11 tests guard this model - 10 generic, 1 singular.

Columns

Column	Type	Nullable	Tests	Description
lap_id		Yes	not_null, unique	PK, FK to stg_laps
dirty_air_intensity_lag1		Yes	not_null	One-lap-lagged dirty-air intensity from int_lap_air_state
dirty_air_tax_s		Yes	not_null, expect_column_values_to_be_between	Per-lap dirty-air slowdown in seconds. θ_air × dirty_air_intensity_lag1. Positive (slower cost). Bounded [0, 5.0]. θ_air is estimated from the two-arm calibration panel, not defaulted (08q). Because dirty_air_intensity_lag1 is one bit per lap, this column still takes two values per build — 0.0 on a clean-air lap and θ_air on a dirty-air lap — but θ_air is now the fitted +0.1310 s/lap rather than the unfitted 0.5 literal it was through v12. A dose-response on the measured gap (int_lap_air_state.min_gap_s / stg_telemetry_position.distance_to_ahead_m) is the standing follow-up; removing the treated-arm filter is the identification fix, not the measurement fix.
dirty_air_tax_se_s		Yes	not_null	Standard error of the tax estimate via propagation
tax_calibration_confidence		Yes	not_null, expect_column_values_to_be_between	Confidence in the tax [0, 1], as n / (n + 500) over the calibration sample n. Since 08q restored both arms to that panel, n is the full 123,993-lap panel rather than the 28,523 treated laps it was through v12, so this reads ~0.996 rather than ~0.983. It measures calibration SAMPLE SIZE ONLY and is not a statement about whether θ_air is distinguishable from zero in a given season — it is near 1.0 on every season including 2021 and 2024, where the per-season estimate straddles zero.
cumulative_dirty_air_tax_race_s		Yes	not_null	Running race-cumulative sum of per-lap dirty-air tax for each driver
dirtiest_air_lap_in_race_flag		Yes	not_null	TRUE on the lap where this driver’s per-lap tax is at its maximum in the race