DOLLARS and pesos cross the border between America and Mexico in greater numbers than ever. The $400 billion-worth of trade in 2010 made Mexico America’s biggest trading partner after China and Canada. Greenbacks are so common south of the frontier that in some neighbourhoods peso coins are known as cuoras, a mispronunciation of “quarters”.
Lately the relationship between the currencies has been rocky. Between July and November the peso fell by 19% against the dollar, hitting its lowest level since the 2009 financial crisis. It has since bobbed back a little as prospects across the border have improved a tad. Nonetheless, its performance so far in the second half of this year has been the weakest of any Latin American currency.