The Institute for Economic Affairs are dealing with disability and employment on a generational. They are assuming that all disabled people will be able to undertake some form of employment and that these employments are there to be found. In many instances this may be so, but disability covers an extremely wide spectrum and the differing areas of disability also cover a wide spectrum.
In many of these differing areas there will be a substantial number of persons, who through no fault of their own will never be able to be employed due to the extent and nature of their disability.
Unfortunately neither the Government, the media, the Institute for Economic Affairs and others are not taking this into account.
Then to decentralise processing of disability related benefits is opening up the system to a Post Code Lottery, where some parts of the UK will be better dealt with than others. Also it also opens the system up to allocation of priorities as is the situation with health, where the CCGs, Clinical Commissioning Groups are responsible for allocating funding to how they view the priorities in their areas. This could and does mean that some health conditions are dealt with better in some areas than others.
Equality should be available to all.
Also, you should not deal with the rate of increase in disability related benefits from WW2 to now without viewing other aspects of finance, such as salaries, inflation, evolution of the market workplace, improvements in living standards and progression of medical science. For with the latter more persons with disabilities are living longer, but still way behind those who are not disabled and the extent and range of disabilities are more varied.
All this and more needs to be reflected, than the bold statement from the Institute for Economic Affairs.