We investigate whether board-interlocked firms via an audit committee (AC) board member exhibit correlated non-audit service (NAS) purchases, and whether financial reporting quality and future firm performance vary with the amount of correlated NAS purchases from the AC interlock. We find that AC interlocked firms have positively correlated total NAS and three NAS subtypes—Tax, Assurance, and Other—in the overall sample period from 2000 to 2016, and in each of the subperiods pre- and post-SOX (Sarbanes–Oxley Act). Firms with a larger NAS component that is explained by the AC interlock tend to exhibit lower financial reporting quality. We also find evidence that firms with higher AC interlocked NAS purchases are associated with lower future performance, although this association exists only in the pre-SOX period. Overall, the evidence suggests that greater NAS purchases among AC interlocked firms can have a detrimental effect on financial reporting quality and auditor independence. While these detrimental effects are concentrated in the pre-SOX period when there were less restrictions on NAS purchases, we find some evidence that the association with lower financial reporting quality persists in the post-SOX period.

我们调查通过审计委员会（AC）董事会成员联锁的公司是否展示了相关的非审计服务（NAS）采购，以及财务报告质量和未来公司的绩效是否随从AC联锁的相关NAS采购量而变化。我们发现，在 2000 年至 2016 年的整个样本期间，以及在 SOX（萨班斯 - 奥克斯利法案）之前和之后的每个子期间，AC 连锁公司的总 NAS 和三个 NAS 子类型（税收、保证和其他）呈正相关）。具有由 AC 联锁解释的较大 NAS 组件的公司往往表现出较低的财务报告质量。我们还发现证据表明，具有较高 AC 联锁 NAS 购买的公司与较低的未来业绩相关，尽管这种关联仅存在于 SOX 之前的时期。全面的，证据表明，AC 联锁公司之间更大的 NAS 购买可能对财务报告质量和审计师独立性产生不利影响。虽然这些不利影响集中在对 NAS 购买限制较少的前 SOX 时期，但我们发现一些证据表明，在后 SOX 时期，与较低的财务报告质量的关联仍然存在。