Abnormal returns for vertical merger announcements are positive until the late 1990s, and turn negative afterward. As the results of a vertical merger, successive activities in a value chain which has been conducted by different firms are brought in-house in a single firm. This is the reason why antitrust agencies are less likely to contest a vertical merger than a horizontal merger.
The simplest types of chemical formulas are called empirical formulas, which indicate the ratio of each element in the molecule. The empirical formula is the simplest whole number ratio of all the atoms in a molecule. For example: The molecular formula for glucose is C6H12O6.
The forms commonly encountered are empirical, molecular, structural, and projection formulas. An empirical formula consists of symbols representing elements in a compound, such as Na for sodium and Cl for chlorine, and subscripts indicating the relative number of atoms of each constituent element.