重大不利變更條款中的風險分配與交易效率之研究：以應對不確定性的併購契約設計與解釋為核心

Abstract

本研究旨在探討併購契約中重大不利變更條款之設計與解釋。本文深入討論重大不利變更條款的架構、目的、應用，並從法律經濟分析視角，如交易成本理論、風險分配理論、不確定性趨避與資訊不對稱等面向，探究其在提升締約效率、減少交易成本的作用。研究依序考察先進國家在重大不利變更條款的學理、司法解釋、實務發展，以及我國在併購契約重大不利變更條款之設計實務，並考究尚待解惑之處，進而經借鏡外國學理、實務經驗，擬以法律經濟分析相關理論為重心，針對我國實務重新建構出更具經濟合理性與可操作性的應然設計與解釋框架。

在應用與解釋層面，本文主張應採取更精準、具體的語言做定義界定，例如詳細列舉構成重大不利變更之事件類別與標準，以降低爭訟不確定性，又如，可經基礎定義約款框架，未能明確定性之將系統性風險、協議風險及指標性風險分配予併購標的買方，將重大營運風險分配予併購標的賣方。在解釋時也應回歸風險分配架構的效率考量，不僅應關注價值變動的程度，更應著重變動的成因，觀察成因事件是否在併購標的賣方可控制且應當控制的範圍內。另就「重大」判斷，則應考量該不利變更是否超出併購標的買方可接受的獲利範圍。如此，可避免併購標的買方以輕微不利變動為藉口進行投機行為，致併購交易效益承受非理性效率障礙。

This study aims to examine the design and interpretation of Material Adverse Change (MAC) clauses in merger and acquisition (M&A) agreements. It provides an in-depth analysis of the structure, purpose, and application of MAC clauses, and explores their role in enhancing contracting efficiency and reducing transaction costs from a law and economics perspective, including transaction cost theory, risk allocation theory, uncertainty aversion, and information asymmetry. The research systematically reviews the doctrinal foundations, judicial interpretations, and practical developments of MAC clauses in leading jurisdictions, as well as the current practices of MAC clause design in Taiwan. It identifies unresolved issues and, drawing on foreign academic theories and practical experience, seeks to reconstruct a more economically rational and operationally feasible normative framework for the design and interpretation of MAC clauses in Taiwan, with legal-economic theory as its analytical core.

At the level of application and interpretation, this thesis advocates for the use of more precise and specific language in defining MAC clauses, such as explicitly enumerating the categories of events and materiality thresholds that constitute a material adverse change, in order to reduce litigation uncertainty. Through a structured definition clause, the framework should allocate systematic risk, agreement risk, and indicator risk to the acquirer, while assigning major operational risks to the seller of the target company. In interpreting the clause, efficiency-based risk allocation should be prioritized; the focus should be not only on the magnitude of the adverse change, but more importantly, on its underlying cause—specifically, whether the cause falls within the seller’s sphere of control and responsibility. As for determining whether a change is "material," the benchmark should be whether the adverse change has exceeded the acquirer's reasonable expectations for profitability. This approach prevents acquirers from opportunistically invoking minor adverse changes as a pretext to escape the deal, thereby safeguarding the overall efficiency of M&A transactions against irrational or inefficient disruptions.