The global challenge of climate change mitigation is hampered by disagreements on cost allocation between developed and developing nations. Developed countries, responsible for the majority of historical carbon emissions, advocate for cost-effectiveness irrespective of historical context. Conversely, developing nations argue for greater responsibility from historically high-emitting countries. This research addresses this conflict by employing an economic experiment. The study aims to determine whether awareness of historical emissions affects cost-sharing decisions in climate change mitigation efforts, specifically evaluating whether information about past actions impacts the willingness of current generations to bear the burden of addressing past emissions.

Prior experimental studies examined the impact of previous-stage decisions on climate negotiations. However, these studies often involved the same participants in both stages, potentially confounding personal responsibility with collective responsibility. This research differentiates itself by employing separate generations of participants: a first generation creating wealth and emissions, and a second generation inheriting the wealth and negotiating mitigation costs. This design more accurately reflects the temporal disconnect between industrialization in developed nations and the current climate crisis. Existing literature reveals diverse perspectives on historical responsibility for climate change, ranging from moral responsibility for historical emissions to arguments dismissing historical responsibility due to a lack of knowledge or practical constraints. This study remains agnostic towards these viewpoints and focuses on the effects of information on cost-sharing willingness.

A two-stage economic game was designed. In the first stage, two first-generation participants (A1 and B1) representing two fictional countries (A and B) engaged in wealth generation through effort tasks. Piece rates varied, creating disparities in both wealth and emissions. Production increased wealth but exponentially increased climate change mitigation costs for the second generation. In the second stage, two second-generation participants (A2 and B2) inherited the wealth generated by A1 and B1, respectively, and negotiated mitigation cost allocation using an ultimatum game with the strategy method. The game included two treatments: a History treatment where second-generation participants were informed about the first generation's actions, emissions, and the resulting wealth and costs, and a Baseline treatment where this information was withheld. 103 first-generation participants and approximately 100 second-generation participants were recruited for each treatment. Data analysis included OLS regressions and random-effects GLS regressions to account for potential dependencies in the data. Strategies were classified based on participants' responsiveness to historical emissions, and an additional baseline treatment (Baseline with Predecessors) was added to rule out alternative interpretations.

The key finding is that in the History treatment, participants inheriting greater historical emissions offered to pay a significantly larger share of mitigation costs (β = 0.53 in Model 1, Table 1). This relationship between historical emissions and willingness to pay was far weaker in the Baseline treatment (β = 0.13). The interaction term between historical emissions and treatment showed a stronger effect of historical emissions in the History treatment (β = 0.40 in Model 3, Table 1). Furthermore, analysis of individual strategies revealed that a significantly higher percentage of participants adopted cost-sharing strategies proportional to historical emissions in the History treatment (22% versus 0% in the Baseline). The probability of reaching an agreement was similar across treatments. However, a secondary analysis revealed that, within the History treatment, proposers with higher historical emissions made significantly higher offers, while those with lower emissions made lower offers. The additional Baseline with Predecessors treatment confirmed the stronger effect of historical emissions in the History treatment, although the difference was less pronounced compared to the original Baseline. The ex-post rationality analysis showed proposers in the History treatment behaved more rationally when accounting for historical emissions. Lastly, agreements were less likely when there was greater inequality in historical emissions or wealth.

The results suggest that transparency concerning historical emissions is crucial. Informing participants about the link between past emissions, present wealth, and current mitigation costs significantly alters willingness to share the burden. This effect appears driven by a sense of collective responsibility, even across generations without direct interaction. The similar agreement rates across treatments suggest that while information on historical emissions affected offers, it did not decisively impact the overall success of negotiations. The greater success of agreements when wealth and emissions were similarly distributed highlights the role of inequality in hindering international climate action.

This study demonstrates a strong causal link between information about historical emissions and willingness to contribute to climate change mitigation. Transparency regarding historical responsibility appears key to fostering greater cooperation. Future research should explore the influence of national identity and the non-linear effects of historical emissions on negotiations involving multiple countries and rounds of interaction.

The study's limitations include the use of a simplified two-country model, a one-shot negotiation game, and the use of fictional countries. The assumption of complete knowledge of historical emissions by the first generation might not accurately reflect historical realities. Future research should address these issues by considering more complex models and incorporating real-world factors.