This study presents a meta-analysis of contract attributes for the adoption of agrienvironmental practices. We use a data set of 290 observations drawn from 79 studies reported in empirical studies using the Discrete Choice Experiment (DCE) method. The present meta-analysis explores the impact of methodological choices related to the timing of the DCE (design stage, implementation stage, and analysis stage) on farmers' contract preferences regarding the adoption of agrienvironmental practices. We first highlight the possibility of simplifying the contract attributes to propose two representative clauses: commitments and incentives. Several biases were found related to designing, implementing, and analyzing a DCE. We show that these results are relevant for two specific clauses (Duration and Quality). Finally, our contribution provides guidance for mitigating potential biases that can affect the results when DCE is implemented.