Nudges and threats: soft versus hard incentives for tax compliance
利用瑞典税务局的高质量行政数据，研究发现标准执法威胁（将债务移交执法机构）使欠税者支付率提高9个百分点以上，而温和的助推（如提醒信）对不面临执法风险的群体效果几乎与威胁相当，但对面临执法风险的群体无显著影响。
Abstract We study what induces delinquent wage earners to pay their taxes due, using high-quality administrative data from the Swedish Tax Agency. We find a strong effect of the standard enforcement regime: a threat of having the debt handed over to the Enforcement Agency increases payments by more than 9 percentage points (from a baseline of 58%). When including actual enforcement, payment increases by 19 percentage points compared with those who do not risk enforcement. In a field experiment, we compare these effects of standard enforcement to those involving much milder nudges, consisting of letters reminding tax delinquents to pay their taxes due. We find that a ‘pure nudge’ (i.e., the inclusion of an extra sheet of paper with no valuable information) has an effect of around 7 percentage points for those who do not risk enforcement upon non-payment, that is, an effect almost as large as for the threat of enforcement. However, the same nudge has no detectable effect on the group that is subject to enforcement. Finally, we find a small additional effect on payments from social norm messages both for those who risk enforcement and for those who do not.