Outsourcing, subcontracting work to another company, has always been a part of doing business. Firms hire other firms to do work they cannot do themselves or can have done more cheaply elsewhere. With today’s global economy, the practice is now so prevalent that even companies in the business of outsourcing are outsourcing work to others.

Wealthy nations routinely send all types of work to countries where labor costs are cheaper, but currently the most frequently outsourced jobs are in information technology (IT), software, and customer service. Japan, Western European countries, and the United States outsource the most work, and India and China take in the most.

Language skills are a decisive factor in where work is sent, with India and the Philippines serving English-speaking clients, Argentina working with Spain, Mexico serving Spanish speakers in the United States, and China handling Asian languages such as Mandarin, Cantonese, and Korean. As a preponderance of corporations conduct business in English, the bulk of outsourcing jobs in recent decades have gone to India, where its status as a former British colony resulted in millions of people speaking English as their first language. About half of India’s outsourcing work comes from the United States, with about a quarter from European countries and the remainder from countries such as Japan and Australia.

Some of the largest outsourcing firms in the world have headquarters in India. However, confronted with increasing demand, a looming shortage of skilled workers, and rising wages at home as the Indian economy grows, some of those outsourcing companies are now turning to other countries to help meet their own staffing needs. They outsource largely to China but also to dozens of other countries, including the Philippines, Mexico, Brazil, Saudi Arabia, and, in some cases, the country where the work originated. For example, a U.S.-based software company might outsource IT support to a company based in India, which then subcontracts part of the work to a company in the United States.

Much of the IT support market is now moving to China, where a vast supply of highly trained people are willing to work for lower wages than people in India. With newer Chinese companies not yet well established in the outsourcing business, Indian firms are opening branches there, where their knowledge of English and well-developed managerial skills give them an advantage, at least for now, in dealing with international clients.

Outsourcing has long been a source of controversy, with opponents pointing to the loss of jobs and damage to the economy in the home country and proponents viewing the savings in labor costs as a boon to business. The receiving countries generally consider the well-paying jobs a benefit to their economy, but employees are not always happy with the work. Staff turnover can be high when employees have to work long night shifts to coincide with the business day in the outsourcing country.

India remains the outsourcing epicenter for now, with China slowly catching up, but the situation will continue to change. Once wages rise high enough in India and China, foreign workers somewhere else will be as enticing to outsourcing countries as India and China now are to Europe, Japan, and the United States.