The Olmeca oil refinery is one of Mexican President Andres Manuel Lopez Obrador's infrastructure mega-projects AFP

One runs an aerospace parts maker, the other works in a restaurant near a major new oil refinery -- both women will vote in Mexican elections this weekend, but they could be from different countries.

Mexico's economy has long operated at different speeds, with an industrial north closely linked to the neighboring United States outpacing a less developed south.

It is an imbalance that outgoing President Andres Manuel Lopez Obrador has tried to address with infrastructure megaprojects including the oil refinery, a tourist railway and a new airport serving Caribbean beach resorts.

In the northern border state of Nuevo Leon, Blanca Lopez manages a bustling aerospace components maker on the outskirts of the manufacturing hub of Monterrey.

The parts coming off the production line might end up in airplane seats or engines, said Lopez, whose family grew the company from a fledgling business in her father's workshop to a supplier for clients including US giant Boeing.

"It's a source of pride to know that you're doing things well and that your people are well trained," the 41-year-old businesswoman told AFP.

The factory is part of an aerospace cluster that has helped to boost Nuevo Leon's economic output to eight percent of the national total.

Business leaders are optimistic that the border region will benefit from the so-called "nearshoring" trend of companies moving manufacturing from Asia closer to the huge US market.

About 1,400 kilometers (870 miles) to the south, Sandra Sanchez waits for customers at a restaurant in Chiltepec.

The picturesque coastal town is located near a new oil refinery that Lopez Obrador's government built in his home state of Tabasco with an investment of $16.8 billion.

"We hope that the people who come will contribute to the town," the 34-year-old said next to chairs that for the moment were empty.

Sanchez said she noticed a difference under Lopez Obrador, who has an approval rating of more than 60 percent but is only allowed to serve one term under the constitution.

The leftist leader showed the potential to "lift up Tabasco" and the entire country, she told AFP.

"The economy did change a lot since his six-year term began," Sanchez said.

Like others in Chiltepec, she has already had a taste of the fruits of the infrastructure investment.

When the refinery was under construction, the restaurant where she works benefited from the arrival of hundreds of construction workers.

At that time, its takings could total 120,000 pesos -- just over $7,000 -- in a single weekend.

Now that construction has finished, that figure has dropped to about $1,200.

Experts say the economy of southern Mexico has been boosted not only by the refinery but also the Maya Train tourist railway, another one of Lopez Obrador's emblematic projects in the Yucatan Peninsula.

Tabasco's economy grew 6.8 percent in 2023 -- the most of any Mexican state -- which analysts at the Spanish bank BBVA attributed to government-linked construction work.

Nuevo Leon and Tabasco could not be more different.

Nuevo Leon is ranked fourth of 32 states in a competitiveness index calculated by the Mexican Institute of Competitiveness, based on an assessment of innovation, infrastructure, the labor market and environment.

Tabasco is in 20th place.

Nuevo Leon had a poverty rate of 16 percent in 2022, compared with more than 46 percent in Tabasco, according to official data that showed an improvement of eight percentage points in both compared with 2020.

With the infrastructure investment, southeastern Mexico "will never again be forgotten," according to Lopez Obrador, whose ruling-party ally Claudia Sheinbaum is leading the race to replace him.

However, some experts doubt how sustainable the economic boost will be in the long-term, not only in Tabasco but in other traditionally poorer southern states such as Chiapas and Oaxaca.

Statistics suggest that the number of formal jobs in Tabasco has fallen compared with the time of the refinery construction, said Jesus Carrillo, an expert at the Mexican Institute of Competitiveness.

When the refinery was being built, "everyone was happy," said Juan Gabriel Cordova, a 49-year-old fisherman.

Now "complaints about a lack of work are going to start," he added.