A better gauge of an economy's use of resources is "total factor productivity" (TFP), which tries to assess the efficiency with which both capital and Labour are used.
It only becomes an issue when there's no other factor that the customer can use to gauge your product's value.
当没有其他可让客户用来估计你的产品价值时它才会成为问题。
3
It is justified that the integral of the gauge potential along path of not only electron but also scalar particle or spinor particle will contribute a geometric phase factor.