Labor hours per 100 gallons of gasoline

Labor hours per 100 gallons of gasoline, version 1.0

Classification. Derived: deterministic arithmetic over stored values; every number is reproducible from the stored ids named in the observation's metadata.

Formula. For each month, the mean of the weekly regular gasoline prices whose date falls in that month, times 100, divided by average hourly earnings for the month. The result is hours. The custom function labor_hours_gasoline_monthly does the weekly-to-monthly mean; the engine has no such transform.

Engine rendering: The custom function labor_hours_gasoline_monthly over the whole component dataset, for each geography and period. A period with any component missing produces no value. Rounded to 3 decimals.

Components.

• gasoline_price_weekly, metric us-gasoline-regular-price (USA). US regular all-formulations retail gasoline price, weekly (EIA via FRED GASREGW).
• hourly_earnings, metric us-average-hourly-earnings (USA). Average hourly earnings of all employees, total private (BLS CES0500000003 via FRED).

Windows and alignment. Monthly, United States. The electricity price and earnings are monthly series matched on the month. The gasoline price is weekly (reported for Mondays); the weeks whose date falls in a calendar month are averaged into that month before dividing, and the ids of the averaged weeks are recorded on the row.

Missing data. A period is produced only when every component has a value for it; nothing is interpolated, carried forward or estimated.

Rationale. Fuel is the other household energy purchase with a stable physical unit and a long price record; together with electricity it covers most of what a household spends on energy, in work time rather than dollars.

Limitations. Average hourly earnings are a mean across all private employees, not a median and not after tax, so the hours are those of an average earner, and a distribution shift changes them without any change in prices. Prices are national averages; households in different states face different electricity and gasoline prices. Both components are nominal, which is the point: no deflator is involved, the measure is a physical quantity against a wage. Gasoline is regular grade, all formulations; premium and diesel are not covered.

Revision. Recomputed at every derived pass; a changed component value produces a new observation row and earlier rows are kept. A change to anything that affects the numbers is a new formula version (the spec hash is on every row and a changed spec under a used version is refused).