Mortality Risk Valuation in Policy Assessment

Annex A. Systematic review procedure

Description

The objective of the review is to collect all existing studies that provide a primary estimate of the value of statistical life (VSL). Under this criterion, both stated preference (SP) and revealed preference (RP) studies that are published in English and that report original VSL estimates based on primary data anywhere in the full text are considered. The systematic review follows the PRISMA 2020 guideline (Page et al., 2021[1]).

Identification

The databases used to build the meta database include the Web of Science, Econlit, and PubMed for full-text publications of all document types written in English published between January 1, 2009, and December 31, 2023.

The search terms used to identify publications include “VSL,” “VoSL,” “value of statistical life,” “value of a statistical life,” “willingness to pay for mortality risk reduction,” “value of prevented fatality,” “VPF,” “value of risk reduction,” “value of reduced mortality risk,” “VRMR,” “value of a mortality risk reduction” and “value of a life year.” The exact combination of query terms is shown below:

• WoS & Econlit

  • "VoSL" OR "value* of statistical li*" OR "value* of a statistical li*" OR "willingness to pay for mortality risk reduction*" OR "value* of a prevented fatality "OR "value* of prevented fatalit*" OR "value* of risk reduction*" OR "value* of reduced mortality risk*" OR "VRMR" OR "value of a life year" OR "value of a mortality risk reduction" OR "value* of mortality risk reduction*" OR "value* per statistical life" OR (("VSL" OR "VPF" OR "statistical li*") AND ("WTP" OR "willingness to pay" OR "WTA" OR "willingness to accept" OR "human capital" OR "stated preference" OR "revealed preference" OR "CVM" OR "hedonic" OR "CE" OR "contingent valuation" OR "choice experiment*" OR "wage differential*"))

• PubMed

  • "VoSL" OR "value of statistical li*" OR "value of a statistical li*" OR "value of risk reduction*" OR "VRMR" OR "value of a life year" OR "value of mortality risk reduction*" OR "value* per statistical life" OR (("VSL" OR "VPF" OR "statistical li*") AND ("WTP" OR "willingness to pay" OR "WTA" OR "willingness to accept" OR "human capital" OR "stated preference" OR "revealed preference" OR "CVM" OR "hedonic" OR "CE" OR "contingent valuation" OR "choice experiment*" OR "wage differential*"))

In a first step, all studies reporting VSL estimates regardless of their method were identified. In a second step, these studies were screened in order to only keep SP and RP studies that report original VSL estimates. Next, the reference lists of all selected studies were cross-checked with previous meta-analyses and review articles to identify additional relevant studies. Finally, selected group of economists with extensive experience in VSL studies reviewed the resulting list of VSL studies for potential missing work which resulted in several added studies.

Selection

To be eligible for inclusion in the meta-analysis, a publication had to be an original research study written in English using an SP or an RP method to elicit VSL estimates. This selection criterion excluded any article that did not include primary VSL estimates, that was not written in English, and any articles that used previously reported values to estimate the VSL, such as the value transfer method or meta-regression analysis. After removing these, the authors screened the full text of the remaining studies.

Hypothesis

Collected studies reveal global variation in observed VSL estimates regarding countries, time, methodology, and scope characteristics. The original study’s quality, value elicitation method, sample and population characteristics and risk types are considered.

References

[1] Page, M. et al. (2021), “PRISMA 2020 explanation and elaboration: Updated guidance and exemplars for reporting systematic reviews”, The BMJ, Vol. 372, https://doi.org/10.1136/BMJ.N160.