The primary purposes of this study are to measure major relationships describing the responses of different components of sheep and beef farming capital stock in New Zealand to changes in economic conditions, and to investigate the way in which this capital stock has changed over time. These objectives are pursued by attempting to specify an econometric model that recognises joint production between sheep and beef cattle and also takes account of joint firm/household decision making. Aggregate New Zealand data for the period 1952/53 to 1973/74 are fitted to the model using Full Information Maximum Likelihood estimation.