Incapacity for work is not a medical but an economic concept. The difference between the earnings somebody could have had without health problems, and the possible earnings with health problems determine the degree of incapacity for work. Social security physicians and vocational experts together judge the degree of incapacity for work in discussion with the client. The physician judges the general possibilities of the client. The vocational expert selects possible jobs the client should be able to do. The disability allowances are relatively low. Treating physicians should take into account this and other negative aspects of incapacity for work.