What would people do if it were 1 peso 1 dollar? I remember that very well. That may not recur but the rate may not always be so favorable to expats with hard currency. Would you tip as generously as some people here say they do? Also if you are earning pesos, you think in pesos and not in USD blue exchange rates. That makes you be more cautious I think. A problem of tipping significantly above the local norm is that it can create expectations that locals can't live up to. I do agree that people who leave a pittance after an expensive meal are mean-spirited.