Hypotheses derived from the public choice and other literatures on the relationship between ownership and performance were tested on ten UK organizations which had undergone status change, within the public sector or between the public and private sectors, in the last twenty years. Results on tests of performance in productivity, employment, and financial ratios against change in status, competition and internal management failed in most cases to support the thesis that change in ownership improves enterprise performance, even in its more sophisticated form where ownership change is assumed to be accompanied by increased competition and improved managerial incentives.