We show that larger trades incur lower trading costs in government bond markets (“size discount”), but costs increase in trade size after controlling for client identity (“size penalty”). The size discount is driven by the cross-client variation of larger traders obtaining better prices, consistent with theories of trading with imperfect competition. The size penalty, driven by the within-client variation, is larger for corporate bonds, during major macroeconomic surprises and during COVID-19. These differences are larger among more sophisticated clients, consistent with information-based theories.

中文翻译：

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规模折扣和规模惩罚：债券市场的交易成本

我们发现，在政府债券市场上，较大的交易会产生较低的交易成本（“规模折扣”），但在控制客户身份后，交易规模的成本会增加（“规模惩罚”）。规模折扣是由较大交易者获得更好价格的跨客户差异驱动的，这与不完全竞争的交易理论一致。在重大宏观经济意外和新冠肺炎 (COVID-19) 期间，公司债券因客户内部差异而受到的规模损失更大。这些差异在更成熟的客户中更大，这与基于信息的理论一致。