Since our research programme was launched in 1970 the entire economy of the industrialized west has suffered misfortunes which have operated unfavourably for disadvantaged workers of all kinds. Overfull employment has succumbed to massive unemployment. Trade unions even talk of sharing out the precious activity. By contrast, evidence, including our own, shows that work has come to be regarded by some as an optional alternative to benefit, sometimes financially unfavourable. From the angle of our concern in this book, perhaps the most significant change is the payment in the United Kingdom of a range of subsidies to perfectly fit and healthy workers, thus driving a coach and horses through early arguments deployed against the principle of subsidising the disadvantaged, though practical difficulties of implementation remain (Department of Employment 1973a: 26-7). Whatever view is taken of all this, whatever degree of intervention in the labour market is accepted, knowledge of the capabilities and weaknesses of different categories of disadvantaged workers is needed if steps are to be taken to assist them more effectively, with or without subsidy. In the case of the mentally ill, this has hitherto been lacking except in fragmentary or anecdotal form, or as derived from studies conducted in laboratory conditions. Our purpose has been to make a start on remedying the deficiency though we are aware that a very great deal remains to be done.