NEW UPDATE: Completed trials may now upload and register supplementary documents (e.g. null results reports, populated pre-analysis plans, or post-trial results reports) in the Post Trial section under Reports, Papers, & Other Materials.
Making People Pay their Debts: The role of salience, information, and computational costs in a tax amnesty
Last registered on July 18, 2017


Trial Information
General Information
Making People Pay their Debts: The role of salience, information, and computational costs in a tax amnesty
Initial registration date
July 18, 2017
Last updated
July 18, 2017 6:00 PM EDT
Primary Investigator
Inter-American Development Bank
Other Primary Investigator(s)
PI Affiliation
Inter-American Development Bank
Additional Trial Information
In development
Start date
End date
Secondary IDs
This document describes the pre-analysis plan of a set of interventions that will take place in the city of Santa Fe, Argentina. In these interventions we will evaluate the role that messages play on the probability that taxpayers will cancel their debt with the Tax Administration by subscribing to a payment plan in the context of a tax amnesty. The interventions are the following. First, a group of recent debtors -debt less than five years old- will be divided into 3 groups. The control group will receive the old notification. Treatment one will receive a new notification that is more colorful and presents easy to follow descriptions of the payment plans. Treatment 2 will receive the new notification but including the computation of interests saved under each one of the payment plans also. The second intervention has been designed for those who have older debt that is close to prescribing. These taxpayers will be divided into two groups, one receiving the old notification and one receiving the new notification, including the analysis of savings. With these interventions we plan to evaluate the role of messages, salience, and information on debt payment, on the selection of a payment plan, and on compliance with current tax obligations (spillover). While there are several recent field experiments looking at the role of messages on tax payment, there is no evidence for this in the context of a tax amnesty. Moreover, even though it has long been considered that reducing transaction and informational costs should be a relevant policy instrument, there is little to no evidence about the role that reducing the costs of understanding the specifics of a payment plan could have on tax payment and compliance behavior.
External Link(s)
Registration Citation
Castro, Edgar and Carlos Scartascini. 2017. "Making People Pay their Debts: The role of salience, information, and computational costs in a tax amnesty." AEA RCT Registry. July 18. https://doi.org/10.1257/rct.2329-1.0.
Former Citation
Castro, Edgar, Carlos Scartascini and Carlos Scartascini. 2017. "Making People Pay their Debts: The role of salience, information, and computational costs in a tax amnesty." AEA RCT Registry. July 18. http://www.socialscienceregistry.org/trials/2329/history/19615.
Experimental Details
The field experiment consists on two interventions. The first intervention includes those taxpayers who have accumulated debt in some or all periods between January 2013 and March 2017. This group of taxpayers was randomly split into three groups. The first group was assigned to a control or placebo. The placebo group will receive the old CDA, which includes a verbal description of each plan and the total due amount after discounting the corresponding amount of the one payment plan. As mentioned, this CDA has been in used for several years now and most taxpayers have grown accustomed to it. The Treatment 1 group will receive a new CDA that includes many of the improvements noted before: (i) it is more salient; it is printed in color; (ii) it includes a moral message; (iii) it explains better the different benefits and costs of each payment plan. The Treatment 2 group will receive a new CDA which also includes the amount of interests the individual is saving under each one of the plans. This information is personalized for each taxpayer.

The second intervention includes those taxpayers who also owe bills from January 2011 to December 2012. This period is relevant because absent any action from the government those debts would prescribe. Henceforth, before the debts are ready to prescribe the government sends those debts and taxpayers to judicial enforcement. This group of taxpayers was split into two groups. The first group, control or placebo group, receive the old CDA. The treatment group received a similar new CDA than treatment 2 above but including also a deterrence message highlighted in red. The message says (in Spanish) ``If you decide not to pay your outstanding debt, your account will be assigned to judicial enforcement''.

Every CDA includes a payment coupon that allows the taxpayer to make effective payment if she decides to make only one payment. Otherwise, the CDA informs the taxpayer the procedure to follow to subscribe to the plan and make the first payment.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
The dependent variables of the two interventions will be: (a) Enrollment: a dichotomous variable that will take value one if the taxpayer chooses to enroll in any amnesty payments plan, zero otherwise (i.e., the extensive margin); (b) Enrollment_j: a set of dichotomous variables, one for each payment plan, that takes value one if the taxpayer chooses to enroll in the plan j and zero otherwise (i.e., the intensive margin); (c) Paid, which takes value one if the monthly bill is paid, and zero otherwise.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
From the universe of taxpayers, we removed those who had no debt and were not part of the interventions, and those who only owed some or all of 2017 bills (6,340 taxpayers). The reason to eliminate this group was that the status of these taxpayers is likely to change within the period of randomization and the intervention -they could have paid their debt. The total number of taxpayers in the experiment is 54,700.

Because we are working with a sample with a high degree of heterogeneity, we divided the sample into strata to facilitate the balance between treatment and control groups. The strata are made upon the taxpayer's average compliance for the period of interest (2011-2017), and whether they have or not outstanding debt originated in 2012 or before. The latter is a stratum by itself (Category 1). For the rest of taxpayers, we distributed them in strata according to tax compliance: Category 2 are those who paid less than 10\% of the bills; Category 3 are those who paid between 10\% and 90\% of the bills, and Category 4 are those who paid 90\% of the bills or more. In total we have four strata.
Experimental Design Details
Randomization Method
To select treatment and control groups, we run 1,000 iterations to select a random draw that shows the best balance for all the pre-experimental variables using two criteria: (i) the minimum difference in the average of treatment and control groups, and (ii) the maximum standard error for this difference. The combination of both criteria leads to the highest t-statistic of the difference between treatment and control group. The set of pre-experimental variables comprises lot area in $m^{2}$, building area in $m^{2}$, monthly tax amount in March 2017, and the average monthly compliance rate between 2011 and 2017.
Randomization Unit
Individual taxpayers
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
54,700 taxpayers with debt
Sample size: planned number of observations
54,700 taxpayers with debt
Sample size (or number of clusters) by treatment arms
Intervention 1:
Control= 12737; T1=12738; T2=12740
Intervention 2:
Control=8243; T1=8242
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Intervention 1=0.0146 Intervention 2=0.0218
IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan
Analysis Plan Documents
Making People Pay their Debts: The role of salience, information, and computational costs in a tax amnesty

MD5: 16f874564a19e54e364b7154288312dc

SHA1: 6497ca6373b40a98ae09f8d601c6e391ffb40b02

Uploaded At: July 18, 2017

Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)