You can readily identify an e-Passport, because it has a unique international symbol on the cover. Electronic System for Travel Authorization (ESTA) ESTA is an automated system that determines the eligibility of visitors to travel to the United States under the Visa Waiver Program (VWP). Authorization via ESTA does not determine whether a traveler is admissible to the United States.
Two to three weeks before the flight date, the price quotes start increasing. This is the time when business travelers start booking. While price drops are still possible, a chance of a price increase is much higher if you wait to book within this time period.
In the graph, prices increase by a modest amount from P1 to P2. Since the actual rate of inflation remained constant during this time, we can consider the price increase shown in the graph a representation of inflationary pressures that were building at the time due to the elimination of economic slack.