Airports are unusual investment vehicles. They are highly regulated property assets with characteristics of utilities, shopping malls and monopolies, at least in a local context. They operate in a relatively high-growth arena, with global air passenger demand forecast to grow at 5 percent a year for the foreseeable future, and with the number of passengers increasing by just less than twice the rate of the growth in real GDP. Their reason for existence is to provide access to airlines to land and takeoff safely, and they charge those airlines for the privilege. However, those very same airlines engorge and spew passengers in a flow to provide a captive market for a series of ancillary selling potentials, from car parking and coffee shops to duty-free sales and high-end luxury goods. After all, those passengers have to be given something to do while waiting for their flights.

Success breeds success. The larger the airport gets in terms of passenger throughput, the greater the