THE DAGENHAM AND BATTERSEA EMPLOYMENT EXCHANGE AREAS
O UR choice of area in which to study the mobility of the adult male population was limited, by the funds available, to areas within easy reach of the centre of London. Financial considerations also limited the size of the sample whose past movements could be studied, and influenced the decision to study the employed rather than the residential population of an area. 1 Once we had taken this decision it was apparent that the Ministry of Labour Employment Exchange areas were, as administrative units for employment purposes, the most appropriate districts in which to sample the employed population. The boundaries of these areas are not as a rule identical with those of Local Authorities, but they represent fairly distinct employment centres within the London region.