Analyzing different pathways by which socialecological systems can loose resilience and enter trajectories of collapse constitutes an important aspect of our quest towards understanding resource sustainability. This paper's goal was to better understand the effect of a particular class of disturbance-the accumulative effects of routine stressors-in the context of marine social-ecological systems. To that effect, we built a system dynamics model using empirically collected institutional and biological field data of an artisanal fishery in the Gulf of California, Mexico. Among our findings, we identified different scenarios under which even very small endogenous changes in the relationship between ecological and institutional variables can send a seemingly resilient system into a trajectory of collapse. We discuss why these types of disturbances are so difficult to prevent and be identified by the users of the resource, as well as potential strategies to address these challenges.

Despite being an important concept to assess vulnerability of ecological systems, the literature is still unclear on how to measure resilience in different systems and therefore on how well the concept of resilience translates into the practice of analyzing the vulnerability of social systems. This paper presents a practical procedure to assess the degree of resilience of socio‐ecological systems which builds on system dynamics analysis, in particular on loop polarity analysis. It shows that socio‐ecological systems lose resilience when they exceed certain thresholds in which dominant polarity of their feedback structures shifts sign. Copyright © 2012 System Dynamics Society.

As sociedades que mais se desenvolveram economicamente sob a ótica da NEI foram as que criaram as instituições que mais reduziram custos de transação. O presente trabalho pretende avaliar em que medida as obras clássicas da nossa historiografia sobre o período colonial podem ser lidas, com proveito, à luz das contribuições recentes dos principais textos neo-institucionalistas. Diversas questões interessantes são levantadas nessa nova leitura; uma delas é a de se teria sido o empreendimento colonial e as instituições que ele criou, e que irão influenciar toda a história posterior do Brasil, uma obra de indivíduos movidos pelo interesse próprio, que constituem uma sociedade peculiar no novo mundo, ou um “negócio do rei”, que produz no Brasil uma sociedade sem coesão e destituída de projeto próprio, a qual, mesmo após a independência, não disporá de vigor institucional para constituir um governo diferente da monarquia portuguesa.
The societies more developed economically, under NEI'S hypothesis, were the ones that created the institutions that more reduced transaction costs. The present work intends to evaluate if the classic works of our historiography on the colonial period can be read with advantage on the light of the neo-institucionalists recent contributions. Several interesting subjects are underlined in that new reading. One of them is it would have been the colonial enterprise and the institutions that it created, and that will influence the whole subsequent history of Brazil, a work of individuals moved by the own interest, that constitute a peculiar society in the new world. Or a "business of the king", that produced in Brazil a society without cohesion and deprived of own project, which, even after the independence, will not have institutional vigor to constitute a government different from the Portuguese monarchy

O objetivo deste trabalho é fazer uma análise sistêmica da dinâmica da produção cafeeira no Brasil com foco no período 1900-1930. A motivação para abordar a questão sob a ótica da dinâmica de sistemas (system dynamics) é que essa metodologia é especialmente adequada para modelar processos sujeitos à complexidade dinâmica, como os ciclos de produção de commodities. Mostrar-se-á que modelar e simular a dinâmica da produção de café no Brasil com essa metodologia permite, em primeiro lugar, realizar experimentos contra-factuais que possibilitam avaliar quantitativamente o efeito de políticas de defesa de preços, como as políticas de valorização, complementando a já extensa e rica literatura sobre o assunto. Em segundo lugar, será sugerido que abordar a questão sob esta ótica ajuda a extrair insights de política não apenas para o café como para outras commodities, das quais o Brasil ainda depende de forma importante para manter o equilíbrio em suas contas externas.

We propose that the ability of opinion leaders of influencing ordinary farmers to adopt more sustainable practices in irrigation systems during extremely dry periods depends on the type of social network in which they are embedded. We show that in disassortative networks, where influent people link preferentially to relatively disconnected ones, e.g., in large gravity-fed irrigation systems, opinion leaders can be important to encourage the adoption of sustainable practices because they tend to present relatively high betweenness centrality scores, which indicates a greater ability to bridge clusters of otherwise disconnected people. In assortative networks, i.e., in networks in which people tend to connect to other similar individuals, on the other hand, it seems that the ability of leaders to influence other people is not directly related to their betweeenness centrality degree. We conclude than that betweenness centrality is a source of influence only in disassortative networks, that additionally present low clustering coefficients. This suggests that opinion leaders may be important to help bridge the informational gap between agencies and stakeholders in some, but not in all, irrigation systems, in order to pave the way for the adoption of measures to cope with extreme droughts, like the one Brazil is currently experiencing.