Notes from the desk.

Working analyses on aviation demand, aircraft economics, and market cycles. Method stated, assumptions exposed, diagnostics reported — including the ones that did not go the way the model wanted.

Demand forecasting Aircraft economics Market cycles

Published — 1 note

Research note · Demand forecasting · April 2025

Forecasting U.S. domestic flight volume with a seasonal ARIMAX model

Monthly arrivals are seasonal, capital planning is not. A model that carries the seasonal structure forecasts ten held-out months to within 1.72%; the same model without it misses by twice as much — and fails its residual diagnostics outright.

Method
SARIMAX(1,0,2)(2,0,0)[12]
Data
BTS · 2010–2024
Out-of-sample MAPE
1.72%
Read the note
Line chart of monthly U.S. domestic arrivals from 2010 to 2024, showing seasonal oscillation, the 2020 collapse, and the subsequent recovery.
Total domestic arrivals by month, United States, 2010–2024. Source: Bureau of Transportation Statistics.

In progress

What the desk is working on.

Research is published here as it is completed rather than on a schedule. Current lines of work concern aircraft unit economics and the behaviour of demand models under structural breaks — the conditions in which the note above is weakest.

Data and estimation code for published work are available on request. Corrections are welcome and will be recorded on the note itself rather than quietly amended.