The particular approach to problems of economic policy adopted by the writer is briefly outlined in the introduction. This is that political decisions in the economic field should be analised within their historical context, and with reference to
(a) the targets of policy;
(b) the instruments of policy;
(c) the data, or economic factors outside the control of government.
These three elements, when functionally related, constitute a decision model. The approach is mainly inspired by Professors Frisch and Tinbergen with this difference that more emphasis is placed on the historical and institutional background of the decision-problem and that the use of mathematics was confined to its philosophy rather than its technique.