In the UK, studies using the WERS dataset have arrived at different conclusion about the penetration of the high performance model, ranging from two per cent to 26 per cent of companies (see Keep et al. 2002). Other datasets have suggested lower results; Guest et al. (2000) found only one per cent of companies in the Future of Work survey use three quarters of 18 progressive practices. Thompson (2000) found generally higher results for aerospace with some 20 per cent of UK aerospace establishments using high performance HR practices to a significant degree. This would indicate that despite strong evidence of positive effects, employers are either not necessarily convinced that adoption of such processes will work for them or find the process of adopting them too difficult. It is also likely that there are sectoral variations in uptake.