Cross-posted to the EA forum. Introduction Like last year and the year before, I’ve attempted to review the research that has been produced by various organisations working on AI safety, to help potential donors gain a better understanding of the landscape. This is a similar role to that which GiveWell performs for global health charities, and somewhat similar to an securities analyst with regards to possible investments. It appears that once again no-one else has attempted to do this, to my knowledge, so I've once again undertaken the task. This year I have included several groups not covered in previous years, and read more widely in the literature. My aim is basically to judge the output of each organisation in 2018 and compare it to their budget. This should give a sense for the organisations' average cost-effectiveness. We can also compare their financial reserves to their 2019 budgets to get a sense of urgency. Note that this document is quite long, so I encourage you to just read the sections that seem most relevant to your interests, probably the sections about the individual organisations. I do not recommend you skip to the conclusions! I’d like to apologize in advance to everyone doing useful AI Safety work whose contributions I may have overlooked or misconstrued. Methodological Considerations Track Records Judging organisations on their historical output is naturally going to favour more mature organisations. A new startup, whose value all lies in the future, will be disadvantaged. However, I think that this is correct. The newer the organisation, the more funding should come from people with close knowledge. As organisations mature, and have more easily verifiable signals of quality, their funding sources can transition to larger pools of less expert money. This is how it works for startups turning into public companies and I think the same model applies here. This judgement involves analysing a large number papers relating to Xrisk that were