A study by four Ivy League economists has shown that gentle text-based nagging can induce people to save more. As part of a study, they worked with banks in the emerging markets of Bolivia, Peru and the Philippines.
When people opened accounts and were encouraged to commit to saving certain amounts, the banks randomly assigned some customers to receive reminders via text. Some notes reminded customers that they had focused on a particular goal, others reminded savers that there were incentives for saving (like higher interest rates), and some did both.
The conclusion: "Individuals who received monthly reminders saved 6% more than individuals who did not. They were also 3% more likely to reach their savings goals by the end of the savings program." The most effective form of messaging was one that reminded people both that they needed to save in order to reach a personal goal and that there were incentives for doing so.