What is the relationship between accounting costs, opportunity costs and the degree of contribution (i.e. productivity) of an input? How does productivity influence an economy's standard of living and corresponding economic growth ? Do firm's consistently evaluate resource decisions as it relates to the flexibility of input (labor & capital) substitution in their business model ? Explain.

List & explain some measures (econ principles) which are important in determining growth in production for an economy ? Think about the principles & interconnectivity of the circular flow model