Walmart already had a history of controversial behavior in Mexico. Most notably, in November 2004, despite widespread opposition, the company opened a 72,000-square-foot store within the boundaries of the 2,000-year-old city of Teotihuacán, which features the Pyramids of the Sun and the Moon (“the place where men became gods” — or consumers?). Walmart has also built a supermarket on forested land in the resort town of Playa del Carmen, in Quintana Roo — though the permit for the building later turned out to have been granted for another site, on the island of Cozumel. The question now is who allows this, and in exchange for what?

Will the federal investigation discover how many Walmarts were built on the quicksands of corruption? Marcelo Ebrard, the mayor of Mexico City, is carrying out his own investigation, but considering that his brothers have been Walmart executives, I don’t have much hope that the truth will emerge. The other day I visited a Walmart, and one of the teenage packers, who are unsalaried and work for tips, confided in me that they had been forbidden to say anything to the press about their employer. They were told to consider themselves lucky to have a job at all.

In this country, corruption exists at all levels, from magnates to street vendors. It seems easier to get something done with a bribe than to fill out myriad forms and wait in lines to confront evasive civil servants. According to a recent study, companies shell out approximately 10 percent of their earnings to corrupt officials. In the last 30 years, the Mexican economy has lost more than $870 billion to corruption, crime and tax evasion.

The consequences of this corruption are clear. When devastating earthquakes hit Mexico City in 1985, an alarming number of shoddily constructed public buildings — schools, hospitals and government offices — were destroyed. Our school system has been hijacked by the politically powerful teachers’ union, and around 90 percent of the budget is eaten up by teachers’ salaries, though many on the payroll work for the union or hold political office instead of teaching.

Extortion and protection rackets flourish alongside drug trafficking. President Álvaro Obregón, who was assassinated in 1928, once said that “no general can resist a 50,000-peso cannon blast,” a precursor to today’s “plata o plomo” — silver or lead, the drug cartel’s offer to officials of a bribe or a bullet.