<P> The U.S. produces approximately 18 % of the world 's manufacturing output , a share that has declined as other nations developed competitive manufacturing industries . The job loss during this continual volume growth is the result of multiple factors including increased productivity , trade , and secular economic trends . In addition , growth in telecommunications , pharmaceuticals , aircraft , heavy machinery and other industries along with declines in low end , low skill industries such as clothing , toys , and other simple manufacturing have resulted in some U.S. jobs being more highly skilled and better paying . There has been much debate within the United States on whether the decline in manufacturing jobs are related to American unions , lower foreign wages , or both . </P>
what are the main sources of economic growth in the us currently
telecommunications pharmaceuticals aircraft heavy machinery