In the first variant of the model assuming symmetrical countries, we include (1) a hyperbolic cost function that represents the existence of a natural conservation ceiling in each country and (2) local conservation benefits to describe the benefits of preserving biodiversity at different scales. For symmetrical countries, we get stable coalitions of no more than 2 signatories. These coalitions are smaller than those obtained in climate agreement models using square cost functions. In addition, our result supports the existing literature, which finds that the inclusion of local benefits has no influence on the size of a stable coalition if the conservation function is additive and the benefits in conservation are linear. Climate change, as well as climate protection regulations, have an impact on biodiversity. This is why a programme has been developed within the framework of the Convention on Biological Diversity (CDB), which focuses specifically on climate change and biodiversity. Therefore, resolute cooperation between these two environmental conventions would be very important, in addition to the joint lup of the Rio Conventions (CBD, UNFCCC and the Un Convention on Combating Desertification – UNCCD). For example, the negative effects on biodiversity could be related to the large-scale production of energy crops. B oppose the climate effects. In this paper, we develop an IEA stability model for biodiversity preservation, which contains three characteristics that we consider to be the key to understanding biodiversity agreements. We study the stability of the IEA in the case of countries that are both symmetrical and asymmetrical, without transfers and including transfers. We will deduce important results that we are resusping and discussing in this section.

From the analysis, we find that cooperation between countries in a bilateral asymmetry game is robust in terms of changes in (1) the overall maximum level of biodiversity conservation. The species equipment in each country, but positively related to the increase in local benefits of conservation, although the higher local benefits of conservation in larger coalitions. they are not necessarily converted to more effective IEAs. This is because the additional incentives for conservation are due to high local benefits, regardless of a country`s participation in an IEA. Therefore, in a highly stable IEA, cooperation gains are relatively small in this case compared to cases where local performance is weak. Finally, the adoption of symmetrical countries, often used in IEA models, is often too restrictive: the costs and benefits for preserving biodiversity vary considerably from country to country. Many countries, well equipped in terms of biodiversity wealth, are among the poorest in terms of income (swans and married 2012). In addition, the natural conservation ceiling also varies from country to country.

Our model makes an innovative contribution to the literature for the protection of international biodiversity by including (1) a natural conservation ceiling in each country, combined with a hyperbolic cost function, (2) the integration of local conservation benefits to present the various criteria on which the benefits of biodiversity are perceived, and (3) the subdadivity of the global conservation function.