|Laws and doctrines|
|Enforcement authorities and organizations|
The Merger guidelines are a set of internal rules promulgated by the Antitrust Division of the United States Department of Justice (USDOJ) in conjunction with the Federal Trade Commission (FTC). The Trade Practices Act 1974 is an act of the Parliament of Australia. The International Competition Network is an informal virtual network that seeks to facilitate cooperation between Competition law authorities globally A competition regulator is a Government agency, typically a statutory authority, sometimes called an economic regulator, which regulates and enforces The United States Department of Justice Antitrust Division is responsible for enforcing the antitrust laws of the United States. For animal rights group see Justice Department (JD The United States Department of Justice ( DOJ) is a Cabinet department The Federal Trade Commission ( FTC) is an independent agency of the United States government, established in 1914 by the Federal Trade Commission Act These rules, which have been revised a number of times in the past four decades, govern the extent to which these two regulatory bodies will scrutinize and/or challenge a potential merger on grounds of market concentration or threat to competition within a relevant market. In Economics, market concentration is a function of the number of firms and their respective shares of the total production (alternatively Competition is a rivalry between individuals groups nations or animals for territory or resources In Competition law the Relevant market defines the market in which one or more goods compete
The merger guidelines have sections governing both horizontal integration and vertical integration. In Microeconomics and Strategic management, the term horizontal integration describes a type of ownership and control In Microeconomics and Management, the term vertical integration describes a style of Management control.
The first merger guidelines set forth by the USDOJ were the 1968 Merger Guidelines, which remained largely unchanged until 1982. For animal rights group see Justice Department (JD The United States Department of Justice ( DOJ) is a Cabinet department The 1968 guidelines were developed by former U.S. Assistant Attorney General Dr. Many of the divisions and offices of the United States Department of Justice are headed by an Assistant Attorney General. Donald Turner, an economist and lawyer with expertise in the field of industrial organization. An economist is an expert in the Social science of Economics. Industrial Organization is a field of Economics that studies the strategic behavior of firms the structure of Markets and their interactions  These merger guidelines were criticized in some quarters as being overly concerned with issues of market structure such as barriers to entry and concentration ratios at the expense of efficiency and economies of scale. In Economics and especially in the theory of Competition, barriers to entry are obstacles in the path of a firm which wants to enter a given Market In Economics, the concentration ratio of an Industry is used as an indicator of the relative size of firms in relation to the industry as a whole  They were, however, a step forward in two ways: they gave more accurate advice to corporate management as to when and how mergers would be examined, and brought new economic ideas into antitrust enforcement, specifically the "structure-conduct-performance" model of industrial organization. Industrial Organization is a field of Economics that studies the strategic behavior of firms the structure of Markets and their interactions 
In 1982, Associate Attorney General Bill Baxter, under the authority of U.S. Attorney General William French Smith, released a new set of guidelines, which made heavier use of modern concepts of microeconomic theory, including the using the Herfindahl index to determine market concentration. The Associate Attorney General is the third-ranking official in the United States Department of Justice. The United States Attorney General is the head of the United States Department of Justice (see) concerned with legal affairs and is the chief law enforcement William French Smith ( August 26 1917 &ndash October 29 1990) was an American lawyer and the 74th Attorney General of the Microeconomics is a branch of Economics that studies how individuals households and firms and some states make decisions to allocate limited resources typically in markets The Herfindahl index, also known as Herfindahl-Hirschman Index or HHI, is a measure of the size of firms in relationship to the Industry and an In Economics, market concentration is a function of the number of firms and their respective shares of the total production (alternatively  The newer guidelines took a more favorable view of economies of scale and efficiency of production as rationales for integration.  Moreover, they raised the level of market concentration necessary for the government to scrutinize mergers, effectively treating competition as a means to greater efficiency rather than as a goal in and of itself.  This was quite a controversial approach at the time: some antitrust lawyers saw it as a loosening of previous restraints on corporate consolidation, and some State Attorneys General responded to Baxter's changes by tightening merger enforcement at the state level. The state attorney general in the United States is an executive office in all 50 State governments. 
The guidelines were revised again in 1984.  The only remaining portion of the 1984 guidelines which remains in effect is Section Four, which governs the examination of market effects of vertical integration. In Microeconomics and Management, the term vertical integration describes a style of Management control. These guidelines were later replaced by the 1992 Merger Guidelines, which represented a fine-tuning of previously established tools and policies, such as the SSNIP test and rules governing the acquisition of failing firms. In Competition law, before deciding whether companies have significant Market power which would justify government intervention the test of Small but Significant and Non-transitory The most recent revision of the merger guidelines was made in 1997, which are still effective as of 2007. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.