UK air travel over the coming two decades, projected from income and population growth alone. Its fitted series is too short to re-run the model from earlier years.
Conditions and method
Status: projection (income-only central projection from income per person and population; supply-side expansion, network formation and low-cost entry are not modelled).
The baseline is an income-only projection from the 2024 passenger level. The 5th and 95th percentile lines are a 90% band around it that takes its income path to 2030 and the 2024 level as given, so it covers part of the uncertainty only and cannot be added to the scenario spread. The United Kingdom’s fitted series is too short to re-run the method from earlier years. In the other markets’ re-runs, on the curve fitted to all years, the band held the outcome in every window ending by 2019 for the United States and, in the rest, in 55% of those 5-year windows, 25% of 10-year and none of 15-year.
The chart counts passengers a year, not passenger-kilometres. For the United Kingdom the count is CAA (the UK Civil Aviation Authority) terminal passengers at UK airports, scheduled and charter, with a domestic trip counted once. Other markets count passengers on their own national definitions.
The projection leaves out supply-side, network and low-cost-carrier growth. Its baseline grows about 0.75% a year. The fitted curve’s median income elasticity averages 0.443; the United Kingdom has no long-run elasticity on the ladder to compare it with.
Baseline: the IMF growth forecast to 2030, then income growth rising or falling toward one assumed long-run rate, about 1.8% a year, which has no external source. Optimistic and pessimistic: income growth to 2030 is 1.4 and 0.6 times the baseline’s, on the UN high and low population variants; by 2044 most of the gap between them comes from population (about 84%). Structural deceleration: from 2031 income growth converges to 1.2% a year. Disruption: income growth is 3 percentage points lower in 2025 and 2026, less so to 2029, so income stays about 10% below the baseline.
Two refit tests set the method against holding trips per person flat: it did no better one year ahead and was closer several years ahead in most markets; here it was further off one year ahead and could not be scored later. A third, across the pandemic, starts from a predicted level, so its error counts the curve’s gap to the data and across markets is several times the other two; here it is several times its one-year error. Neither refit passed the project’s own sampling screen, so their figures are less firm than the projection’s. These tests reach 10 years at most; the projection runs 20.
The projection uses passenger data through 2024 and the IMF’s October 2025 growth forecast, which runs to 2030. Later observations exist for some markets and are not used. Income growth per person is IMF real GDP growth minus UN medium-variant population growth. The IMF path embeds its own population projection; the two differ most for Canada, Australia and the United Kingdom. The international share of traffic is held inside its historical range. Short-history markets borrow their curve’s shape from the others.