© 2015.This paper applies a pairwise approach to investigate the validity of the law of one price in the crude oil markets. Price differentials appear smaller between crude oil pairs with similar physical/chemical characteristics and also for pairs within OPEC.
Giulietti, M., Iregui, A. M., & Otero, J. (2015). A pair-wise analysis of the law of one price: Evidence from the crude oil market. Economics Letters, 39-41. https://doi.org/10.1016/j.econlet.2015.02.002