毕竟，他们（或其中一些人）认为，美国实际GDP每年增长4,000亿美元，其中约2,700亿美元用于劳动力，1,300亿美元用作资本。
After all, they (or some of them) argue, the real GDP of the United States is growing by $400 billion per year, with about $270 billion going to labor and $130 billion to capital.