This paper considers the manner in which technology is diffused, with a particular emphasis on the impact on workforce composition as it matures. The lack of quantitative evidence of technology on the medical labour-force limits our knowledge of the full impact of technological change in the healthcare sector. We examine the diffusion of PTCA as it replaces CABG in the treatment of cardiovascular disease in England, estimating the degree to which the workforce reacts to the introduction of the newer technology, through calculating elasticity of supply measures. Using administrative data we trace the complementarity between CABG and PTCA during the mature phase of technology adoption, mapped against an increasing employment of cardiologists over cardiothoracic surgeons. Our findings show evidence of indication creep as PTCA is increasingly expanded to older and sicker patients, and that cardiothoracic surgery, other than CABG, increases in a manner consistent with replacement activity and cardiothoracic employment
