Comments on Migration and Economic Mobility in Tanzania David McKenzie

Main message Migration is development – large source of consumption growth for people in this area non-controversial here, as internal migration, but a controversial statement in international migration (see Lant Pritchett’s work).

Descriptives convincing, and some good steps towards identification Step 1: control for individual differences in levels of consumption (diff-in-diff). Thought experiment: compare two individuals with same initial level of consumption (and same age, education, gender, etc.) – see how much more consumption grows for the person who migrates. Concerns: those who migrate still would have had different consumption growth without migration (e.g. high ability people would succeed in getting out of poverty at home too).

Step 2 Control for (baseline) household fixed effects. Thought experiment is now: take two people in the same household, which has now split up. Compare the consumption growth of the individual who moved to the individual who didn’t move. Issue: why did one person leave the household and not another? (and is this correlated with consumption growth).

Step 3 Try and instrument for migration: Pull: distance to city*male aged 18 to 28 (possible threats: access to trade, local labor market, etc. affected by geography) Push: Rainfall shock*male aged 18 to 28 (surely this affects consumption, if males affected differently by rainfall due to different occupations, etc.) Social relationship: whether head or spouse, age rank (but doesn’t this affect how they would do in a non-migrating split household?).

Discussion Return Migration? How much is there? It is surely not surprising that after 10 years, the migrants who remain away have succeeded. Did those that did less well by migration return? Impact on remaining household members? Do the remaining individuals in Kagera do better if they have a household member move away from Kagera vs leave the household and stay in Kagera? (sign of effect less clear) Consumption at the individual level – is per capita the right measure? Household composition changes with migration – at least try per adult equivalent. Look at BMI – take two malnourished individuals, does the one who migrated have higher BMI 10 years later?