Next-door neighbours were looking down at us through the gap from their tiny dwellings just feet away, as we climbed the stairs to her bedroom - a curtain serving as a door because the lower half was missing.
Paul Seabright, an economist at the University of Toulouse in France, observes that trust in a modern economy has evolved to the miraculous point where people give complete strangers sums of money they would not dream of entrusting to their next-door neighbours.