"Closing borders is naive, the virus will come regardless" - this was the policy assumption that was repeatedly stated until mid-March by the WHO, the EU, as well as responsible authorities in Germany and other countries. Meanwhile, other states had started closing their borders to travellers...

The novelty of our model is to combine models of collective action on networks with models of social learning. Agents are connected according to an undirected graph, the social network, and have the choice between two actions: either to adopt a new behavior or technology or stay with the default...