Public preferences for different natural hazard management approaches and Nature's Contributions to People: Evidence from a discrete choice experiment

Last registered on September 03, 2025

Pre-Trial

Trial Information

General Information

Title
Public preferences for different natural hazard management approaches and Nature's Contributions to People: Evidence from a discrete choice experiment
RCT ID
AEARCTR-0016593
Initial registration date
August 28, 2025

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
September 03, 2025, 8:47 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

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Primary Investigator

Affiliation
Eawag: Swiss Federal Institute of Aquatic Science and Technology & University of Bern

Other Primary Investigator(s)

PI Affiliation
Eawag: Swiss Federal Institute of Aquatic Science and Technology
PI Affiliation
Centre for Development and Environment (CDE), University of Bern

Additional Trial Information

Status
In development
Start date
2025-08-29
End date
2026-04-30
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Due to climate change, natural hazards are expected to become more frequent and intense. Swiss Alpine watersheds are heavily engineered with check dams to control these natural hazards. However, this management approach has failed to balance protection with ecosystem resilience, requires high maintenance and investment costs, and relies on infrastructure that is often nearing the end of its life. Therefore, alternative management strategies need to be developed. To this end, eliciting and understanding public preferences, as well as perceptions of natural hazard management can inform the development of alternative strategies. Thus, this study aims to elicit public preferences and willingness-to-pay for various natural hazard risk management approaches and relevant Nature’s Contributions to People through a discrete choice experiment (DCE) survey. The attributes of the DCE represent alternative protection infrastructures and locally relevant Nature’s Contributions to People. The levels are based on the provision levels of Nature's Contributions to People and economic modelling of alternative protection infrastructures costs. We conduct a DCE survey among the local population of three case study regions in the Swiss Alps, which have different levels of natural hazard risk. The DCE is one module within a broader survey on the relationship with the region (e.g., sense of belonging), environmental attitudes, and risk perceptions. It aims to provide policy-relevant evidence and inform natural hazard management policy options and strategies.
External Link(s)

Registration Citation

Citation
Dölker, Julie Elisabet, Ivana Logar and Astrid Zabel. 2025. "Public preferences for different natural hazard management approaches and Nature's Contributions to People: Evidence from a discrete choice experiment." AEA RCT Registry. September 03. https://doi.org/10.1257/rct.16593-1.0
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2025-08-30
Intervention End Date
2025-10-26

Primary Outcomes

Primary Outcomes (end points)
The primary outcomes are:
1) Respondents' choices between the three choice alternatives (two alternatives showing different natural hazard management approaches and a 'none of the two' alternative without any natural hazard management approach) on each choice card,
2) Differences between choices depending on case study regions and natural hazard risk level (low, medium, high)
3) Willingness-to-pay (WTP) estimates for natural hazard protection management approaches,
4) Differences in WTP estimates for natural hazard protection management approaches between case study regions,
5) WTP estimates for selected Nature's Contributions to People (NCPs)
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The respondents are asked to consider different natural hazard management approaches.

For the main survey, we aim for N=750-950, i.e. N=250-315 per case study region, given the small population size in the case studies and a limited number of potential survey respondents. The pretest involves 107 respondents from a different sample (not case study regions).

The survey encompasses multiple modules: connection and attachment to the region, the DCE, environmental attitudes and socio-demographics. The discrete choice experiment (DCE) includes the following choice attributes: biodiversity, accessibility of the area for leisure activities, local timber, gravel and agricultural production, type of protective infrastructure, the risk to the population, property and infrastructure, and price in form of a tax increase. The survey is hypothetical and the participants are not required to pay for their choices. The data collection process is handled by the research team and survey company under strict ethical protocols.
Experimental Design Details
Not available
Randomization Method
The randomization will be done at the individual level by the survey company.
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
107 respondents for the pretest; we aim for N=750-950 for the main survey
Sample size: planned number of observations
107 respondents for the pretest; we aim for N=750-950 for the main survey
Sample size (or number of clusters) by treatment arms
single arm (choice experiment): between 750 and 950 individuals (250-315 individuals from each case study region)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
ETH Zürich Ethics Commission
IRB Approval Date
2025-04-03
IRB Approval Number
Project 23 ETHICS-112