Steve R. Johnson (UNLV) has published Interpreting State Tax Exemptions, Deductions, and Credits, 51 State Tax Notes 607 (Feb. 23, 2009):

Modern tax statutes serve many purposes beyond simply raising revenue, and the contours of those statutes are shaped by many (and sometimes conflicting) economic, social, and political objectives. Legislatures choose a variety of structural mechanisms — including exemptions, deductions, and credits — to advance those policy goals. Sometimes those features are drafted with less than meticulous precision. Other times, business practices have evolved since enactment of the provisions. In either event, revenue agencies and courts are frequently required to interpret those provisions.

This installment of "Interpretation Matters" concerns one such principle of interpretation: The canon that exemptions, deductions, and credits are construed strictly against the taxpayer. Part I describes the canon. Part II suggests ways by which taxpayers attempt to counter it.