Mexico's Senate unanimously approved the bill, which is a less stringent version of the original law proposed by President Calderon two years ago. According to the Associated Press, the bill was delayed because lawmakers were concerned that the original proposal, which barred all cash purchases of real estate, would hurt Mexico's economy, which relies heavily on cash transactions.

Under the new law, no more than half a million pesos in cash (about $39,000) can be used in real estate transactions, and no more than 200,000 pesos (about $15,500) in cash can be used to buy vehicles and other expensive goods. The law also requires commercial establishments and notaries to report large cash purchases or other suspicious financial activity to authorities, reports El Economista.

A senator from the Institutional Revolutionary Party, Arturo Zamora, told Reuters that the amount of illicit funds laundered each year in Mexico is estimated to range anywhere from $10 to $45 billion.

InSight Crime Analysis

One of the most challengings aspects of tackling money laundering is figuring out the scale of the problem. Estimates of the amount of money laundered each year in Mexico vary wildly, as illustrated by the wide range given by Zamora. According to the Los Angeles Times, some Mexican officials estimate that $50 billion is laundered annually, which would make up three percent of the Mexican economy.

While stronger anti-money laundering laws are a good idea in theory, in order to work they have to be enforced. Mexico already has a number of laws to combat money-laundering on the books, the most recent of which was passed in April 2011 and requires banks, casinos, credit card companies, and other business to establish anti-money laundering procedures. However a report released in April of this year by Mexico's Ministry of Finance stated that only two percent of money laundering investigations in 2010 ended with the accused being sentenced.

It is also worth remembering that no matter the laws, anti-money laundering efforts are inherently difficult. As InSight Crime has previously reported, the fact that the majority of criminal profits are reinvested in criminal activity rather than laundered into the legal economy makes it extremely challenging for authorities to make a significant dent in the flow of illict cash.