Meta‐regression models were originally developed for the synthesis of experimental research where randomization ensures unbiased and consistent estimation of the effect of interest. Most economics research is, however, observational and specification searches may often result in estimates that are biased and inconsistent, for example, due to omitted‐variable biases. We show that if the authors of primary studies search for statistically significant estimates in observational research, meta‐regression models tend to make false‐positive findings of genuine empirical effects. More research is needed to better understand how meta‐regression models need to be specified to help identifying genuine empirical effects in observational research.