A $3 trillion headache

As I sit here, late into the polluted night, still sniffing, sneezing, eye rubbing and throat clearing (sadly not just "I" but "we"), right on cue comes an Economist article showing how LatAm megacities are collapsing under their own unsupported weight. Desperately under-invested, congested, polluted, dangerous, etc. etc., they are a $3 trn collective problem. No surprise that Sao Paulo features prominently. (Just how bad, I wonder, can the even more notorious Mexico City be ?) Before I came here I would never have guessed that the biggest pollution problem happened in winter rather than summer. But if you rely on rain as your main anti-pollution measure, then this driest time of the year is not good. Not good at all.