How did air travel cost change with the invention of a jet engine?

need info from a RELIABLE SOURCE! Doing a research paper and need some answers.

The increased power available from the jet engine not only allowed for faster flights, but for larger aircraft that could seat more people.

With more paying passengers per flight, and more flights available per day for the same amount of aircraft (due to the faster speeds) the costs of air travel came down considerably.

The greatest impact was Jet engines enable the plane to fly at higher altitudes with greater fuel efficiency.

High Altitude also allows the plane to take advantage of the Jet Stream and Fly over weather than around it. The jet stream can work against the aircraft but the greater speed of a jet helps reduce the effect.

Write to United and American airlines public affairs departments, and ask for fares from 1950 and 1970. Ask for the fares between New York and Los Angeles. Tell them it is for a research paper. The 1950 date is before jets, the 1970 date is all jets.

United Airlines
P.O. Box 66100
Chicago, IL 60666-0100

American Airlines
P.O. Box 619616
DFW Airport, TX 75261-9616

Regards,
Dan