Issue Summary

One of the most popular airline-industry parlor games (yes, we've heard there are such things) is which two airlines would be the next dominoes to fall in U.S. airline consolidation. It's been a long parlor game; the last merger was the Alaska Airlines-Virgin America deal in 2016. Speculation has run rife, but Frontier-Spirit long has been a popular guess. The deal, in many ways, makes a lot of sense: Both airlines come from the Indigo Group's ultra-low-cost carrier (ULCC) incubator and share the same DNA; and their route networks and fleets are complementary. The real guessing game now is whether…