"I cannot answer in a black and white fashion that meta-analyses is always better than a single study," he says. "We're just trying to approximate closer to the truth, whatever that truth is." In principle, science depends on cumulative knowledge, but even then these other studies can still tell us something because they map a universe,. The second school of thought is that it is a tool to look at the Cumulative Evidence.
John Ioannidis of Stanford University talks with EconTalk host Russ Roberts about his research on the reliability of published research findings. They discuss Ioannidis's recent study on bias in economics research, meta-analysis, the challenge of small sample analysis, and the reliability of statistical significance as a measure of success in empirical research.