Statistical summarizations of literature review databases using meta-regression analysis provide insight into the differences in past estimates of economic variables such as benefits and price elasticities. The panel nature of the data is an issue that has not received adequate attention in past meta-analyses. This paper conceptually and empirically explores the complexity of stratifying data into panels that model the potential correlation and heterogeneity of past outdoor recreation benefit research. Although our tests of three stratifications of the data did not discern panel effects, the inherent complexity of the data maintains a strong presumption of heterogeneous strata.