Information about historical emissions drives the division of climate change mitigation costs.

Despite worsening climate change, the international community still disagrees on how to divide the costs of mitigation between developing countries and developed countries, which emitted the bulk of historical carbon emissions. We study this issue using an economic experiment. Specifically, we test how information about historical emissions influences how much participants pay for climate change mitigation. In a four-player game, participants are assigned to lead two fictional countries as members of either the first or the second generation. The first generation produces wealth at the expense of greater carbon emissions. The second generation inherits their predecessor's wealth and negotiates how to split the climate change mitigation costs. Here we show that when the second generation knows that the previous generation created the current wealth and mitigation costs, participants whose predecessor generated more carbon emissions offered to pay more, whereas the successors of low-carbon emitters offered to pay less.

One-way routes complicate cooperation in migrant crises.

How can countries cooperate to shelter migrants? We use experimental economics to study the distinct challenges of cooperation in migrant crises. We designed an economic game, pass the buck, where participants are leaders of countries who decide whether to shelter migrants or pass them to the next country. We examine the difficulties posed by one-way migration and differences in wealth. We find that leaders sheltered migrants less often when they received them first on a one-way route, compared to when everyone received migrants at the same time. Moreover, the first leader became more likely to shelter migrants when the last country could return them to the first. When one country was wealthier, the wealthy leader sheltered more and the other leaders passed more. We discuss the implications for international cooperation in migrant crises.