Does Message Framing Matter for Tax Compliance ? Evidence from a WhatsApp Field Experiment

This study evaluates whether low-cost digital nudges delivered via WhatsApp can improve property tax compliance in Gorontalo, Indonesia. In a randomized controlled trial, individuals were as-signed to receive either (i) a soft-tone message emphasizing civic duty and public benefits, (ii) a hard-tone message highlighting penalties and consequences, or (iii) no message (control). Four findings emerge. First, although messages referenced overdue obligations, the soft-tone nudge substantially increased current-year compliance: payment of the fiscal year 2024 bill rose by 9–11 percentage points from two weeks through the payment deadline and remained 9.9 percentage points higher at six months, relative to a 38 percent control mean at the deadline. Second, the soft-tone message narrowed and statistically eliminated the compliance gap between historically high- and low-compliance groups. Third, framing mattered: the soft-tone message consistently outperformed the hard-tone message at longer horizons. Fourth, while the hard-tone message generated short-run increases in compliance, these effects dissipated over time, consistent with intertemporal substitution (treated taxpayers paying earlier rather than more). Overall, the results show that behaviorally informed messaging can meaningfully improve tax collection in low-capacity settings, especially when designed to fit local behavioral and institutional context.