Chart of the Day: When Southwest Comes Calling, On-Time Performance Goes South

| Mon Dec. 23, 2013 12:20 PM EST

Here's an interesting, unintuitive tidbit about the airline market. When Southwest enters a market, it forces incumbent carriers to lower their fares. No surprise there. But according to a recent study, it does more than that. It also reduces everyone's on-time performance:

All three conventional measures of arrival delay indicate that airlines begin responding to the threat of entry before Southwest even threatens the route; incumbents' on-time performance begins to worsen before Southwest actually enters the second endpoint airport, and it continues to do so following Southwest threatening the route, and following entry, as well.

As the chart on the right shows, average travel time for flights starts to increase sharply about four quarters before Southwest begins service in a new market, eventually rising by two minutes three quarters after service begins. The number of flights more than 15 minutes late rises from 18 percent to about 21 percent. Why? The authors find the same effect when other airlines enter a new market, but only if the new competitor is a low-cost carrier. Their guess? Pretty much what you'd expect: "Incumbents worsen [on-time performance] in an effort to cut costs in order to compete against Southwest's low costs."