Which results can we “trust”? What share of results replicate in different literatures in the experimental social sciences? I will discuss several recent large replication projects in mainly psychology and economics, where my coauthors and I have redone experiments published in high impact journals with new and larger samples to see whether the main result replicates. The seminar will also cover our studies with prediction markets and forecasting surveys where researchers attempt to predict these replication outcomes as well as new outcomes. I will also discuss ways to increase the reliability of scientific results, and our recent work on multi-analyst projects and conceptual replications where we either ask researchers to test the same hypotheses on the same data or design experiments testing the same hypothesis.