Staying Connected: Experimental Effects of Coach-Delivered Text Messages in an Adult High School

More than 23 million adults in the United States lack a high school diploma, and most who return to school drop out before graduating. We evaluate a randomized intervention of adult high school students in which coaches delivered text messages that encouraged persistence. We find that assignment to treatment increased graduation by 4.9 percentage points, and the effect of message receipt among compliers is 9.3 percentage points, a 41 percent increase relative to the control mean. The intervention operated on the intensive margin by increasing the number of courses completed, but did not affect student enrollment. The effects of the intervention are concentrated among students assigned to experienced coaches, who customized their messages more extensively. We contextualize the economic impact of the low-cost intervention by comparing labor market earnings of graduates to non-graduates, which implies an earnings benefit of $149 per treated student over four years.