A number of factors influenced the country's slow but steady rise as a manufacturing hub for multinational corporations, including its membership in NAFTA, other trade agreements, cheap labor costs and its proximity to the United States.

It just got a lot cheaper to turn the lights on in Mexico.

But observers point to another recent development that they see accelerating investment in Mexico and boosting economic productivity: Electricity is getting cheaper.

The Mexican government made changes to the country's constitution in 2013, allowing foreign companies to invest in its previously state-controlled oil and gas reserves, and its electricity market, for the first time in roughly 80 years.

The reforms are part of an effort to reverse years of declining productivity growth in Mexico. GDP growth has declined from 6.4 percent in the period from 1950 to 1980 to 2.4 percent between 1980 and 2010, according to a Columbia University report prepared for Goldman Sachs on the energy reforms.

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By opening its energy markets, the government hopes it can draw investors who will help develop its remaining oil reserves, and later, its vast shale gas deposits. But the biggest impact so far has come from changes to the country's electricity policies.

"Probably of all the energy reforms that have been passed, the changes in the electricity sector are going to be most helpful to Mexican productivity and competitiveness," said Duncan Wood, director of the Mexico Institute at the Wilson Center.

"When you come to the electricity sector, peak rates for industrial consumers were sometimes 120 to 130 percent higher than what their counterparts were paying in the United States," Wood said. "When you look on average Mexicans were paying 47 percent more than Americans. So this was a huge drag, given the fact when right across the border you have some of the cheapest electricity rates in the world because of all this natural gas."



Mexico's Federal Electricity Commission chief executive Enrique Ochoa Reza, said in a speech last March that electricity rates for industrial customers have fallen between 18 and 26 percent over March of 2014.