The authors' purpose in this paper is to analyse the financial structure of a life office and, in particular, the relationship between the assets and liabilities of a life assurance fund. This analysis is based upon the principle that the guarantees of future capital security and of long-term interest yield involved in the contracts issued by a life office should be backed either by “matched assets” providing equivalent guarantees of capital and interest or by sufficient free reserves to cover the possible adverse effects of departure from the “matched assets” position.

In Parts I and II of the paper, the principle of “matched assets” is studied in relation to three model offices representing stationary and increasing funds operating under idealised conditions. For each model office the “standard” date-distribution of assets is determined–the distribution which, so far as possible, will insulate the fund from the effects of fluctuations in the market rate of interest upon existing assets and liabilities. The profit or loss resulting from “going long” or “going short”, as compared with the standard asset distribution, is then investigated against the background of a rise or a fall in the general level of interest rates.