A total of 25,000 valid questionnaires were returned, which include 23,895 family-housholds
and 1,643 collective households, involving a total of 100,267 persons. The the questionnaire
addresse five aspects of population migration: (1) the size of population involved;
(2) urban migration and its orientions; (3) the structure of population migrating
and moving; (4) causes; and (5) consequences.