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Do Think Twice, it´s All Right: Effects and Mechanisms of Tax Enforcement Policies
Initial registration date
October 03, 2019
October 04, 2019 11:41 AM EDT
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University of Oslo
Other Primary Investigator(s)
Additional Trial Information
We compare the tax compliance effects of two different tax enforcement policies, a relatively costly desk/correspondence audit and a cheap information treatment with a letter asking filers with “risky” filing behavior to take a second look at their tax returns. To assess the total effect of these enforcement policies, we need to take account of both their immediate effects and their long term effects on future filing behaviour. Audits will detect and correct non-compliance on the spot, but may also change subsequent filing behavior. A letter will not disclose non-compliance, but (some) taxpayers may adjust their filings. A letter may also have long term effects on tax compliance. Based on the short run effects of both treatments, which are easy to measure, we describe how we will test the behavioural effects on future filing. We describe the intervention and lay out some important decisions with respect to coding of variables, definitions of samples and the empirical strategy we will apply.
We work together with the Norwegian National Tax Authorities to compare the effectiveness of these two enforcement policies; a desk based correspondence audit and a “take a second look” letter.
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
Claimed deductions for tax year 2018 (in NOK)
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Partner's claimed deductions for the tax year 2018 (in NOK) and Subjective Detection Risk
Secondary Outcomes (explanation)
Randomly assigned audits and letters
Experimental Design Details
In office by a computer
Was the treatment clustered?
Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
MDE for the main outcome after multiple testing adjustment with 80 % power and a 5 % significance level: 0.07 standard deviations
INSTITUTIONAL REVIEW BOARDS (IRBs)