As a system of production, the economy is the division of labor. Each person produces to satisfy the consumptive ends of other persons and has his own consumptive ends satisfied by others. It follows that a “better economy” is one in which people use their resources to satisfy more valuable consumptive ends that they have. It also follows that the location, nationality, ethnicity, etc. of different persons are not relevant, per se, to the determination of who the best producers are in satisfying the consumptive ends of any person.
Productivity increases over time as persons accumulate capital. If productivity rises sufficiently in some area, then a smaller proportion of people may be needed to produce in that area to satisfy the consumptive ends of everyone. Such a process has occurred with agriculture starting in the second half of the 19th century. The percent of workers in agriculture has fallen from around 70 percent in 1840 to around 2 percent today. The same process started in manufacturing after the Second World War. The percent of workers in manufacturing has fallen since then from around 30 percent to around 10 percent today.
Non-farm employment data are in figure 5 of this article:
Here is a useful short analysis: