Trust, Autonomy & Paternalism: An Experimental Study

Using an online experiment, we study whether trust influences i) the willingness to accept a paternalistic intervention, or in other words, the willingness to decide and ii) the willingness to paternalistically intervene in another person's freedom of choice.

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2025-10-13

2025-12-31

From Part 2 of the experiment:
- Participant A: Willingness to decide
- Participant B: Willingness to intervene

Both primary outcomes are binary variables (yes/no).

From Part 1 of the experiment:
Participant A:
- Amount sent in the trust game (= level of trust)
- Belief in amount returned (as a standard control variable in the trust game)
Participant B:
- Belief in the amount sent (= belief about Participant A’s level of trust)
- Amount returned in the trust game (= level of trustworthiness)
From Part 2 of the experiment:
Participant A:
- Belief about Participant B’s decision to intervene
- Confidence in own (potential) choice
- Confidence in Participant B’s (potential) choice
Participant B:
- Belief about Participant’s A decision to decide
- Confidence in own (potential) choice
- Confidence in Participant B’s (potential) choice

Part 1:
The trustor (=Participant B) will make their choices according to the strategy method.
Beliefs will be incentivized.
Part 2:
Belief about the decision of the other participant will be incentivized.
Confidence will not be incentivized.

We address the research question using a two-part experimental design: Throughout the experiment, participants are matched in groups of two and are randomly assigned the roles of Participant A or Participant B.

In Part 1 of the experiment, the level of trust (for Participants A) and the belief in the level of the other participants’ trust (for Participants B) are measured by decisions and via belief-elicitation in the “Trust Game” (à la Berg et al. 1995).

In Part 2 of the experiment, the paternalism game, Participants A states for a specific decision-making situation whether they want to make their own decision or if they want Participant B to decide for them. Participants B, who has perfect information about the decision-making situation, is asked whether they want to make the decision for Participant A. Participants B receive a fixed payoff independent of their decisions in Part 2. The specific decision-making situation only has payoff-relevant consequences for Participants A.

We implement two treatments between-subjects as induced in Part 1:

After reading the instructions and prior to making their decisions, participants receive the following information on a separate screen depending on the treatment (Control vs. Trust):

Treatment Control: Participants receive general information about the decision situation and the trust game.

Treatment Trust: In addition, participants receive information about the level of trust (for Participants B) or the level of trustworthiness (for Participants A) from prior sessions of the study.

Note: The information is based on two sessions from a pilot study of this study.

Our hypotheses are as follows:
Willingness to decide (Participant A): Trust decreases the willingness to decide.
Willingness to intervene (Participant B): Perceived trust increases the willingness to intervene.

Part 1:

We use the Trust Game (à la Berg et al., 1995) to measure the level of trust (Participant A) and the belief about Participant A’s level of trust (Participant B). These two variables serve to validate our treatment manipulation, i.e. our trust prime. In the trust game, participants are assigned to groups of 2 and randomly assigned either to the role of Participant A (trustor) or Participant B (trustee). Each participant receives 10 experimental points. Participant A decides how much of their endowment they would like to send to Participant B. This amount is then tripled. Participant B decides by means of the strategy method how much of the tripled amount they would send back to Participant A.

In addition, Participant A reports their belief about Participant B’s trustworthiness. Participant B reports their belief about Participant A’s level of trust. Both beliefs are elicited in an incentive-compatible manner.

All decisions are revealed only at the end of the study.

The amount sent from Participant A to Participant B measures the level of trust. Participant B’s belief measures their belief about Participant A’s level of trust.

Both variables are expected to increase under the trust manipulation compared to the control treatment.

We provide Participant’s A with the following information:

Treatment Control: “Before you make your decision, we provide you with the following information: The decisions that you and Participant B make in this part have been widely used to study trust. The amount Participant B chooses to send back reflects their level of trustworthiness.”

Treatment Trust: “Before you make your decision, we provide you with the following information: The decisions you and Participant B make in this part have been widely used to study trust. The amount Participant B chooses to send back reflects their level of trustworthiness. In previous sessions of this study, on average, participants in the role of Participant A benefited most when they placed greater trust in Participant B by sending more than half of their endowment. This trust was met with generous returns from Participant B.”

We provide Participant’s B with the following information:

Treatment Control: “Before you make your decision, we provide you with the following information: The decisions that you and Participant A make in this part have been widely used to study trust. The amount Participant A chooses to send reflects their level of trust.”

Treatment Trust: “Before you make your decision, we provide you with the following information: The decisions that you and Participant A make in this part have been widely used to study trust. The amount Participant A chooses to send reflects their level of trust. In previous sessions of this study, participants in the role of Participant A chose to send, on average, more than half of their endowment.”

Control questions are included to ensure participants’ understanding.

Part 2:

In Part 2 of the experiment, we elicit the willingness to decide and the willingness to intervene. The groups and roles remain the same as in Part 1 of the experiment.

Participant B receives a fixed payment of 30 experimental points. Participant A’s payoff depends on choosing between three shapes: a circle, a triangle, and a quadrilateral. Each shape is associated with a payoff determined by the area of the respective shape. The largest shape yields 30 experimental points, the second-largest yields 20 points and the smallest yields 10 points. The areas are randomized across shapes so that any of the three shapes can be the largest, second-largest or smallest.

The side lengths of the three shapes are not specified in the instructions but are displayed only on the actual choice screen. This ensures that, while reading the instructions, Participant A does not yet know whether they are able to solve the task. To account for individual differences in ability, we elicit math skills in the post-experimental questionnaire. Participant B is informed about Participant A’s task and has full information about the area of the shapes. Participant A is explicitly informed that Participant B has this full information.

Participant A and Participant B have the following decision task:

Willingness for a paternalistic intervention: Participant B indicates whether they want to decide for Participant A (i.e. make the choice for Participant A).

Willingness to decide: Participant A simultaneously decides whether they want to make their own decision or have Participant B decide for them.

If Participant B states to decide, Participant A does not have to choose / cannot choose (independent of their decision). If Participant B states not to decide, Participant A can decide / has to decide (independent of their decision).

Note: The fact that Participant A can search for area calculation on the internet is not a disadvantage. On the contrary, this intensifies the trade-off of Participant B whether or not to intervene. On the one hand, Participant B might hold a belief that Participant A is able to look up the shape areas themselves. On the other hand, Participant B might hold a belief that the search is too complicated and that Participant A might make a mistake in her research. Furthermore, the possibility of using the Internet also intensifies the trade-off for Participant A to decide and to maintain autonomy.

Control questions ensure understanding.

The following working hypotheses result from the comparison of the treatment groups:

H1: Willingness to decide (Trust) < Willingness to decide (Control)
H2: Willingness to intervene (Trust) > Willingness to intervene (Control)

Post-experimental questionnaire:

1) Open-end question on motives behind the Part 2 decision.

2) Furthermore, the following items serve as control variables in addition to socio-demographic data:
- Risk self-assessment
- Alternative measures on trust and trustworthiness
- Reciprocity
- Locus of control
- Desirability of control
- Paternalism preference
- Autonomy
- Need for power
- Need for influence
- Self-assessment of math skills
- General feeling of happiness
- Helping tools

Randomization done by a computer.
Ex-post matching done by a computer.

Individual level.

No

Treatment assignment is individual, but roles A and B are matched within dyads and exposed to each other. (In the data analysis, we control for the clustering at the dyad level with robust SEs that account for the fact that each A and B pair may be correlated.)

One observation per participant.

1400 participants in total with 700 participants per treatment.

Exclusion Criteria:
- Failed Bot-Check at the beginning of the experiment
- Failed attention checks from the post-experimental questionnaire
- Early termination of the experiment

The participant numbers are based on a priori power analysis with G*Power (Faul et al., 2007). This was calculated for a Fisher’s Exact Test. We assume small to medium effect sizes. We also assume a two-sided alpha level of 0.05 and a power of 1-β = 0.8. The calculation results in a required sample size of at least 1300 participants. Due to possible exclusions, we plan with a sample size of 1400 participants.