Industry Specialization Index
The "Industry specialization index" (ISI) is a measure of the degree to which states are more or less specialized in an industry. The more specialized a state is in an industry, the higher the ISI will be. The ISI is computed as the share that an industry is of a state divided by the share that the industry is of the nation, and the resulting quotient multiplied by 100. If an industry is a greater share of a state than it is of the nation, its ISI will be greater than 100; if an industry is a smaller share of the state than it is of the nation, its ISI will be less than 100. The industry specialization index is sometimes called a "location quotient" or "LQ." NOTE: The Industry specialization index unit of measure is not meaningful for the statistic Real GDP by state or for the statistic Chain-type quantity indexes.