Private certification intermediaries reduce the costs of trade by assessing the quality of firms’ products or processes and, in many cases, establishing a standard for making those quality assessments. That cost reduction occurs whenever certification intermediaries mitigate information asymmetries that would otherwise distort trade or block trade entirely. The result is a clear efficiency gain: a repeat-play intermediary supplies its reputational capital and evaluation expertise to sellers who cannot make credible commitments to, or buyers who cannot make independent evaluations of, product quality at a comparable cost.