<span>In addition to the neoclassical theory of investment choice, another way of evaluating a tax incentive structure is through the use of marginal effective tax rates. An attempt is made at present to provide estimates of these rates for Greece, and the research concentrates mainly to the calculation of marginal effective corporate tax rates (i.e. only corporate taxes are considered) while the construction of indices extends to the two categories of capital goods, equipment, and buildings. The theoretical background for constructing these indices is given, with special emphasis attributed to neutrality in the designing of efficient taxation systems. The research showed that the Greek tax incentive system is depressing marginal investments, while it is additionally found that there was a more favorable tax treatment of manufacturing investment in equipment than that of buildings. No attempt on recent formulations of the Greek incentive system was made to provide measures (as for example a net investment credit) that could produce some degree of tax neutrality.</span>