All the high points seem to have been touched upon, save one...make that two.

1) Population growth.

This is a pretty interesting website:

World Population Clock: 7 Billion People (2013) - Worldometers

Quote:

"A tremendous change occurred with the industrial revolution: whereas it had taken all of human history until around 1800 for world population to reach one billion, the second billion was achieved in only 130 years (1930), the third billion in less than 30 years (1959), the fourth billion in 15 years (1974), and the fifth billion in only 13 years (1987). During the 20th century alone, the population in the world has grown from 1.65 billion to 6 billion.

According to the United Nations, world population reached 7 Billion on October 31, 2011. According to the most recent United Nations estimates, the human population of the world is expected to reach 8 billion people in the spring of 2024."

NOW HOLD THAT THOUGHT A MOMENT...

2) There is yet another major consideration few people are discussing, anywhere outside of investment and manufacturing circles...

The global, social, and economic impacts of On-Demand 3D printing. This is a rather LARGE topic, but the main gist of it is this...

It is going to radically reduce the costs of just about anything manufactured anywhere in the world today.

So...

Population growth + radical cost reductions due to a new technology with the impact of the advent of the radio, or electricity, etc.

Could mean very big things for commercial aviation, and the demand for same.

Just a thought...a new twist?...on an old topic.

That said, seems like population growth alone (all else remaining equal) will virtually guarantee increasing demand for commercial flight as the world population grows by another billion between now and 2024.