Amazon.com Inc., needing a more tech-savvy workforce, is offering to pay to retrain its employees and help them switch to more technical jobs at Amazon or elsewhere.

The online shopping giant said Thursday that it plans to spend $700 million by 2025 to retrain 100,000 workers, or a third of its U.S. workforce. The initiative could help Amazon find and keep more workers. With a strong economy and unemployment near a 50-year low, workers have more options, giving employers a tougher time finding help.

“The harder it is to hire workers from the outside, the more sense it makes to invest in training the workers you already have,” said Jed Kolko, chief economist at job site Indeed.

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The training could also help Amazon tame criticism from labour groups and some politicians, including presidential candidates, who say Amazon’s order-packing warehouses have poor working conditions. Workers at a Minnesota facility plan to strike next week during the company’s busy “Prime Day” shopping holiday, saying that they are not paid enough for the speed at which they’re expected to pack boxes. Late last year, Amazon raised the minimum wage for all its U.S. workers to at least $15 an hour.

Most of the in-house training will be free for Amazon employees, the company said. It will offer several programs, depending on skill and job level. A warehouse worker with no college degree, for example, could be trained to become an IT technician who keeps the computers and scanners in a warehouse running smoothly. More high-skilled workers, like those at its Seattle headquarters, could take software engineering classes to switch careers at Amazon or another company.

“While many of our employees want to build their careers here, for others it might be a stepping stone to different aspirations,” said Beth Galetti, a senior vice-president of human resources at Amazon. “We think it’s important to invest in our employees, and to help them gain new skills and create more professional options for themselves.”

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Major retailers like Walmart Inc. and Target Corp. have been raising pay and boosting training to lure and retain employees and give shoppers a better in-store experience. While customers are less likely to come face to face with an Amazon worker, the company said having better skilled talent can help it invent more products and make shopping more convenient for customers. Its Alexa voice assistant, for example, has been a hit for the company, allowing customers to reorder paper towels or play a song by talking to a voice-activated speaker.

Amazon said Thursday that it expects its total U.S. workforce to hit 300,000 this year. Worldwide, it has more than 630,000 employees, making it the second-biggest U.S.-based private employer after Walmart.

Amazon, using its own employment data, said its fastest growing skilled job positions over the last five years include data mapping, data science, security engineering and business analysis. There is also strong demand for workers skilled in logistics and transportation.

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