Between September 30, 1950, and May 2, 1962, the value of the Canadian dollar was allowed to fluctuate. This situation, in conjunction with an abundance of Canadian quantitative data, provided Lawrence Officer with a unique opportunity to test theories concerning an economy under the influence of a fluctuating exchange rate. In order to explain the fluctuations that occurred, Mr. Officer set up a model of Canada's economy for the relevant time period. In contrast to conventional models, the exchange rate is the key variable in the system and the foreign sector receives particular attention because of its primary role in determining the exchange rate.