https://phys.org/news/2019-02-t-mobile-sprint-execs-defending-merger.html

Complicating their task is the fact that urban consumers are paying 22 percent less for cellphone service following AT&T's failed bid to acquire T-Mobile in 2011, a combination rejected by federal regulators as anticompetitive. That data comes from the Bureau of Labor Statistics price index for wireless telephone service.

T-Mobile subsequently launched aggressive promotions and made consumer-friendly changes such as ditching two-year contracts and bringing back unlimited data plans, moves that its rivals soon copied. Merger opponents claim those benefits will disappear if T-Mobile and Sprint no longer competed against one another. Unions have voiced concerns about potential job losses.