While not all delegations in our sample can be easily attributed to specific countries, the national (i.e., Party and Observer) delegations can be. To this end, a more directed analysis of these national delegations can facilitate consideration of not only the group size and gender dimensions of diversity explored above but also group diversity in terms of development and (material and natural) resources. We consider these extended dimensions to be diversity in a set of additional models below. To do so, we first merge measures of log GDP per capita and oil rent (as a share of GDP), both taken from World Bank (2023), to our national delegation observations based on their year of COP attendance. We were able to do so for a majority of our national delegation cases, which altogether corresponded to approximately 15% of our total sample. We then re-estimate our main model specifications for this national delegation sample when (i) controlling for both log GDP per capita and oil rent (Tables AI and AII) and (ii) omitting these additional controls while splitting each model’s national delegation sample by low to moderate (i.e., below sample mean) log GDP per capita or moderate to high (i.e., sample mean and above) log GDP per capita (Tables AIII–AVI).