World Bank characterizes parts of Pakistan's urbanization as 'sterile agglomeration'.

What it does not prove: This is a characterisation, not a measurement: it carries no quantity, and it applies to parts of Pakistan's urbanisation rather than all of it — Karachi and Lahore are not equivalent cases. On its own it cannot show how much productivity the agglomeration failed to generate; the labour-composition and informality evidence does that work.

Memory hook: 'Sterile agglomeration' → density that crowds people without compounding their productivity

Rebuts the claim: 'Urbanisation is itself a growth strategy — move people into cities and productivity follows' — density without firms or services yields neither.