A Generalised Model of Monopsony *

This article presents a general but very simple model in which the supply of labour to an individual employer is not infinitely elastic but the employer can also raise employment by increasing expenditure on recruitment. Using this, it is shown how that division between perfect competition and monopsony is whether there are diseconomies of scale in recruitment. Using a unique British data set containing information on both labour turnover costs and the number of recruits we present estimates that do suggest that there is an increasing marginal cost of recruitment.