Macroeconomic Determinants of Air Passenger Demand in Türkiye: Evidence from ARDL and Nonlinear ARDL Models

This study examines the macroeconomic determinants of air passenger demand in Türkiye using an annual time-series framework that distinguishes short-run adjustment from long-run relationships. The dependent variable is passengers carried by Türkiye-registered air carriers, sourced from the World Development Indicators (World Bank, 2026). Macroeconomic activity is proxied by a chained real GDP index constructed from annual real GDP growth, inflation is measured by consumer price inflation, and the exchange rate is the official exchange rate, local currency units per US dollar, period average (World Bank, 2026). The empirical strategy estimates a baseline autoregressive distributed lag (ARDL) model with policy-regime-sensitive controls and a nonlinear ARDL (NARDL) extension that decomposes exchange-rate movements into positive and negative partial sums to assess potential asymmetry. Augmented Dickey-Fuller diagnostics indicate that the transformed series are suitable for ARDL-type estimation, and bounds-style evidence supports a level relationship among the variables. The results show strong persistence in passenger demand and a positive long-run association with macroeconomic activity, consistent with aviation demand scaling with aggregate economic capacity. Inflation is associated with lower demand, reflecting affordability and macro-stability channels. The exchange-rate channel is economically relevant but theoretically ambiguous in aggregate; while the asymmetric specification allows depreciations and appreciations to have different long-run effects, a formal equality test does not provide statistically decisive evidence of long-run asymmetry in the baseline model. The findings imply that aviation demand projections and planning in Türkiye should account for dynamic adjustment and macro-stability policy regimes rather than rely on static trend extrapolation.