Some benighted tourists come to Mexico City and are overwhelmed to discover that there is a street -- Avenida Presidente Masaryk in Polanco -- where you can shop at outposts of many of the world's luxury retailers.

I am not sure what they expected from the capital of a country with one of the fifteen most active economies in the world -- guys in straw sombreros sleeping while burros drink from troughs?

At the dawn of the 21st century, multinational purveyors of sumptuous goods realized that Mexico's is one of the stablest economies in Latin America. And if it's true that half the people in Mexico City live in poverty, about ten percent of the population -- about 2 million people -- have an enticing amount of disposable income. Some of those people are obscenely wealthy.

At first the brands had an uphill struggle. Traditional Mexicans who are well-off enough to spend five thousand bucks on a Cartier watch are also in the habit of getting on a plane so they can brag to their friends that they bought it in Paris or New York. The best customers of the luxury boutiques here are the nouveau riche, politicians and drug traffickers. (The latter are a retailer's dream, as they pay in cash.)

Polanco, the neighborhood where Avenida Presidente Masaryk is located, is the most central upscale neighborhood in the city. As well as luxury stores, many of the city's best restaurants are there. Patronizing them is a delightful escape, however temporary, from some of the city's harsher realities.

Still, once you're out on the street, it won't be long until you're sent a four-alarm reality check. At a nearby traffic intersection, you're bound to see a five-year-old child selling Chiclets to drivers stalled at red lights.