network to share a common name, brand, intellectual property, and quality standards. Each network has established a global entity to co-ordinate the activities of the network. Until 2020, KPMG was the only Big Four firm not registered as a UK private company, but rather the co-ordinating entity was a Swiss association (verein). However, KPMG International changed its legal structure from a verein to a co-operative under Swiss law in 2003, then to a UK limited company in 2020. For Deloitte, PricewaterhouseCoopers and Ernst & Young, the co-ordinating entity is a UK limited company. Those entities do not themselves perform external professional services, nor do they own or control the member firms. Nevertheless, these networks colloquially are referred to as "firms" for the sake of simplicity and to reduce confusion with lay-people. These accounting and professional services networks are similar in nature to how law firm networks in the legal profession work. In many cases, each member firm practices in a single country, and is structured to comply with the regulatory environment in that country. Ernst & Young also includes separate legal entities which manage three of its four geographic areas: the Americas, Asia-Pacific, and EMEIA (Europe, the Middle East, India and Africa) groups, the fourth area being Japan, which has no larger co-ordination branch. These entities coordinate services performed by local firms within their respective areas, but do not perform services or hold ownership in the local entities. There are rare exceptions to this convention; in 2007, KPMG announced a merger of four internationally distinct member firms (in the United Kingdom, Germany, Switzerland and Liechtenstein) to form a single firm, KPMG Europe LLP. History of mergers Since the 1980s, numerous mergers and one major scandal involving Arthur Andersen, have reduced the number of major professional-services firms from eight to four. Big Eight The firms were referred to as the Big Eight for most of the 20th century, reflecting the international dominance of the eight largest firms: Arthur Andersen Arthur Young Coopers & Lybrand Deloitte Haskins & Sells Ernst & Whinney Peat Marwick Mitchell Price Waterhouse Touche Ross Most of the Big Eight originated in an alliance formed between UK and US audit firms in the 19th or early 20th centuries. The firms' initial international expansion were driven by the needs of British and American based multinationals for worldwide service. They expanded by forming local partnerships, or by forming alliances with