Pure altruism and misjudgement: A bad combination?

Stated preference studies on the value of health risk reductions have found valuations elicited from a private perspective to be both higher and lower compared to valuations elicited from a public perspective. Although relevant, the individual's ability to correctly predict the valuation that other individuals assign to the risk reduction has been insufficiently researched. We aim to verify whether individuals exhibit pure altruistic preferences and if this is the case, whether the presence of pure altruism leads to biased valuation of public risk reductions due to misjudgement about other individuals' preferences. We conduct a large-scale online incentivised experiment as a variant of a public good game in which the individual's final endowment is determined by choices made in the experiment. Results suggest that individuals act as pure altruists and hence try to account for the benefits obtained by others of being insured. The results also suggest that individuals fail to correctly predict other individuals' benefits from the insurance, which leads to non-optimal outcomes and biased valuations.