Answer :
In the long run, the most important source of increase in a nation's standard of living is high rate of economic growth.
What is economic growth?
This refers to continuous increase in the total amount of goods and services produced within a country.
The long run is a period in which all factors of productions are variable hence high rate of economic growth is essential towards a nation's standard of living.
Learn more about economic growth here: https://brainly.com/question/1690575
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