Final answer:
Technology is most frequently identified as the primary contributor to economic growth in the U.S., while human and physical capital typically explain less than half of such growth.
Step-by-step explanation:
In the context of U.S. economic growth, technology is often found to be the main contributor. While both human capital and physical capital are essential components of growth, their combined impacts typically amount to only about half, or even less, of the total economic growth observed. Growth accounting studies aim to delineate the contributions of these three factors—physical capital, human capital, and technology—to economic development.
The part of growth not explained by human and physical capital—the so-called 'residual'—is generally attributed to advancements in technology. This encompasses a broad array of improvements, including scientific innovations, smaller inventions, and even enhancements in management practices or institutional frameworks.