Who is audited? Experimental study of rule-based tax auditing

We employed a game-theoretic framework to formulate and analyze a number of tax audit rules, especially the lowest income reporter audited rule. We explicitly considered the auditor’s resource constraint to choose one target from a continuous type of taxpayer. We then tested the theoretical predictions in a laboratory experiment, using three audit rules: the random, cut-off, and lowest income reporter audited rules. While the cut-off rule is known to be optimal in theory, it has not thus far been examined in a controlled laboratory experimental setting. Contrary to the theory, the lowest income reporter audited rule increased average compliance behavior significantly more compared with the optimal cut-off rule and, especially, the random rule. This holds with and without controlling the subjects’ demographics and attitudes regarding tax payment. This finding is practically important because the tax authorities in most countries assign higher priority to enhancing tax compliance.