Final answer:
U.S. firms have adopted high-performance work systems mainly due to global competition, which is intensified by globalization, advancements in technology, and competitive pressures from countries with lower wages.
Step-by-step explanation:
High-performance work systems have become necessary for U.S. firms primarily due to global competition. The force of globalization and increased competition from foreign producers have made it essential for firms to optimize their work systems to maintain competitiveness. As firms and workers in high-income countries perceive a competitive threat from those in medium-income countries with lower costs of living and wages, the need arises for high-performance work systems that can ensure productive and efficient operation against such global pressures.
The shift from manufacturing to service industries in the U.S. has also played a role, as has a reduced desire for unions, which is affected by workplace protection laws currently in place. However, it is the intense level of globalization and the advanced communications and information technology that have significantly increased the competition from other regions and countries, prompting U.S. firms to adopt high-performance work systems.