Another example: calculating the effect of migration on the socio-economic profile of cities

• Take advantage of:

• SMS matrix, allowing counts of gross migration flows between cities defined as groups of districts
• Table MG109, classifying Moving Groups by NS-SeC on basis of economic position and occupation of RP

• But come up against:

• Have to omit migrant residents who had no usual address last year, and migrants in communal estabs
• Do not know the NS-SeC of non-RPs in Moving Groups with >1 member (2/3rds of MGs)
• Do not know what was person’s NS-SeC status one year ago, not even whether a student or not …