Air traffic has doubled every 15 years and it is expected to continue at the same exponential rate of growth over the next decade. However in economy class over the last 10 years, the legacy carriers have inexorably lost market share in the short-haul market to the LCC (Low Cost Carriers) who are now taking on the legacy carriers on the long-haul market as well. On the other hand, upper classes have largely remained the realm of the legacy carriers with most of them earning over half their revenue from upper class customers while the economy class with 75% to 80% of the seats and about half the space capacity generates less than half, in some cases as little as a third of the revenue. It is also reasonable to assume that, given the market conditions and the marginal profitability of legacy carriers, the economy class is sustained by the more profitable upper class.
