The news: The US Transportation Department launched a probe into airlines’ frequent flyer programs. The investigation will examine how dynamic pricing contributes to fare opacity and how airlines devalue miles.

• For example, it asked airlines to list any changes in their programs over the past six years. This includes how each change affected the dollar value of reward points and what options members received to avoid losing any value or benefits they had already earned.
• “These rewards are controlled by a company that can unilaterally change their value,” said US Transportation Secretary Pete Buttigieg in a statement. “Our goal is to ensure consumers are getting the value that was promised to them, which means validating that these programs are transparent and fair.”