Union Membership and Coverage DatabaseThe Union Membership and Coverage Database is an Internet data resource providing private and public sector labor union membership, coverage, and density estimates compiled from the Current Population Survey (CPS), a monthly household survey, using BLS methods. Economy-wide estimates are provided beginning in 1973; estimates by state, detailed industry, and detailed occupation begin in 1983; and estimates by metropolitan area begin in 1986. The Database, constructed by Barry Hirsch (Georgia State University) and David Macpherson (Florida State University), is updated annually.