In this book interrelated factor demand models are surveyed. New methods are developed and are analysed empirically using Dutch and U.K. time series data. New methods are discussed for obtaining closed form solutions of linear ratinal expectations models, providing deeper insights into the identification of structural parameters of underlying theoretical models; recently developed time series techniques are applied in order to estimate structural parameters and test for model specification, stationarity and stability through time; new models are developed in which the rather stringent and questionable restrictions of symmetry generally imposed upon stochastic adjustment models of labour demand are relaxed, the models are analysed empirically using time series data of Dutch and U.K. manufacturing production and nonproduction workers.