The Impact of Proactive Communication on Client Behavior: A Field Experiment in the Turkish Banking Sector

This study investigates the causal effect of proactive telephone communication on client behavior in the context of investment product maturity at a Turkish bank. Framed within the scope of Nudge Theory, the study assesses whether phone calls—though significantly more costly than digital channels—can effectively prompt timely client action, reduce opportunity costs, and improve client retention. Using a randomized field experiment (N = 200), clients were assigned to either receive a phone call or standard digital notifications. The results indicate that phone calls significantly accelerated reinvestment actions by approximately five days and reduced potential interest loss across all customer segments. However, no significant impact was found on satisfaction scores or 3-month churn rates. Qualitative feedback suggests that product features such as interest rates and limits may drive satisfaction more than communication methods. The findings suggest a strategic balance between digital nudges and targeted high-touch interventions.