The law of contracts, trusts and corporations as criteria of tax liability

The general law of contracts, trusts and corporations may be thought to provide clear and stable criteria for the operation of revenue laws. But experience suggests this expectation may be overoptimistic. This is not to urge increased legislative resort to criteria preferring substance over form, with the attendant temptation to impose what constitutional doctrine would stigmatise as arbitrary imposts. It is to urge legislative vigilance in the selection of particular criteria to implement policy objectives, and to reiterate the necessity for a good tax lawyer to keep up-to-date with the general law.