This paper aims to examine how the cost structure of certified public accountant firms changed after the accounting reform of 2005. Korea enacted various accounting reform acts adopting Sarbanes-Oxley Act in 2005. Our sample comprises 1,230 firm-year observations from 1997 to 2012. The sample period is decomposed into two sub-periods: pre-reform (1997–2004) and post-reform (2005–2012) periods. We estimate a multi-product translog cost function to determine whether there are significant changes in the economies of scale during the pre- and post- reform periods. The estimated cost function suggests that overall and product-specific economies of scale prevailed during the full sample, pre- and post-reform periods. However, overall economies of scale lessened after the accounting reform and the economies of scale seemed to be depleted for the larger firms during the full and post-reform periods. As for product-specific scale economies after the reform, the marginal costs of producing Audit and Accounting increased, whereas those of producing Tax services declined. The economies of scale in business advisory services remained constant before and after the accounting reform. The results gleaned from this study may provide CPA firms with managerial implications regarding the changes in cost structure after the accounting reform.

中文翻译：

---

监管改革前后的成本函数估算：来自韩国注册会计师服务业的证据

本文旨在研究2005年会计改革后注册会计师的成本结构如何变化。韩国于2005年通过了《萨班斯-奥克斯利法案》颁布了各种会计改革法案。我们的样本包括1997年至2012年的1,230个公司年度观察。样本时期被分解为两个子时期：改革前（1997-2004）和改革后（2005-2012）。我们估算了多产品的对数成本函数，以确定在改革前和改革后的规模经济中是否存在重大变化。估计成本函数表明，在整个样本，改革前和改革后期间，总体和特定于产品的规模经济普遍存在。然而，会计改革后，整体规模经济有所减少，在整个改革期和改革后时期，大型企业的规模经济似乎都已枯竭。对于改革后的特定产品规模经济，生产审计和会计的边际成本增加，而生产税收服务的边际成本下降。会计改革前后，商业咨询服务的规模经济保持不变。这项研究得出的结果可能为注册会计师事务所提供有关会计改革后成本结构变化的管理建议。会计改革前后，商业咨询服务的规模经济保持不变。这项研究得出的结果可能为注册会计师事务所提供有关会计改革后成本结构变化的管理建议。会计改革前后，商业咨询服务的规模经济保持不变。这项研究得出的结果可能为注册会计师事务所提供有关会计改革后成本结构变化的管理建议。