Technical comment on "Fairness considerations in global mitigation investments".

In an otherwise excellent analysis of fair regional shares of global mitigation investments, Pachauri et al . (Policy Forum, 9 December 2022, p. 1057) dramatically overestimate developing countries' 'capability' to invest by estimating GDP using purchasing power parity exchange rates. Since internationally sourced investment goods must be paid for at market exchange rates, capability-based interregional finance flows should be vastly larger.