Imputing Missing Values in the US Census Bureau's County Business Patterns
The County Business Patterns data published by the US Census Bureau track employment by county and industry from 1946 to the present. Two features of the data limit their usefulness to researchers: (1) employment for the majority of county-industry cells is suppressed to protect conﬁdentiality, and (2) industry classiﬁcations change over time. We address both issues. First, we develop a linear programming method that exploits the large set of adding-up constraints implicit in the hierarchical arrangement of the data to impute missing employment. Second, we provide concordances to map all data to a consistent set of industry codes. Finally, we construct a user-friendly, 1975 to 2016 county-level panel that classiﬁes industries according to a consistent set of 2012 NAICS codes in all years.