Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper analyzes the consequences of ignoring the multi-indexed structure with cross-sectional and panel-data gravity models of bilateral trade for inference. We estimate log-linear and generalized-linear gravity equations of bilateral trade. Ignoring multi-way clustering in the data at hand leads to misleading inference regarding the relevance of preferential trade-agreement memberships of different kinds.