Berry, William and Richard Fording. “Measuring State Tax Capacity and Effort.” Social Science Quarterly (March 1997): 158-66.

The writers calculate estimates of the Advisory Commission on Intergovernmental Relations' tax-capacity and tax-effort indexes for all missing years between 1960 and 1991, in order to create a data set that will be beneficial in a wide range of cross-sectional and pooled analyses. Their estimates are based on a mixture of interpolation, extrapolation, and regression-based strategies: They assess empirically the quality of the estimates produced by each strategy, and their decisions about which strategy to use for which years of missing data are driven by the results of these tests.