Abstract
This study examines the interplay between air passenger transport and international tourism through the role of GDP (Gross Domestic Product) and trade openness in 11 key markets of Singapore. Co-integration tests indicate that although air passenger transport and international tourism may not be individually stable in some markets, their fluctuations are strongly and durably related. The estimation results using a combined SARIMA (Seasonal Autoregressive Integrated Moving Average), X (exogenous factors), and GARCH (Generalized Autoregressive Conditional Heteroskedasticity) model show that there is a strong interrelationship between air passenger transport and the number of international tourists to Singapore, but air passenger transport is less sensitive to fluctuations in the number of international tourists. GDP and trade openness also have significant impacts on the demand for both sectors, but at different levels across markets. The cyclical, seasonal, and external shock effects found in air passenger transport and international tourism indicate the diversity in behavior and characteristics of each market. The research results provide a basis for managers and policymakers to forecast and formulate development policies for tourism and air transport.