Returns to scale increases efficiency by performing with less as a result of increased inputs. Economies of scale yield lower or higher average costs of production due to increased production.
The indicators of returns to scale analyze the variation of the activity of a company relative to the variation of its inputs. Indicators of economies of scale are the same, but are evaluated in monetary units (cost of production and factors of production) and non-physical units (kg metal sq tissue, number of rooms, etc). The unit change does not affect the analysis, and the two terms are frequently interchangeable.
In production, returns to scale relates to variations in output due to proportional alterations in inputs, that is, inputs appreciate by a constant factor. Whenever output shoots up by a proportional shift this translates to constant returns to scale (CRTS).
And in the event that output gains by a margin lower than the proportional alteration, this points to decreasing returns to scale (DRS). While output increments by a margin above that proportion, constitutes increasing returns to scale (IRS).
The economic analysis focuses on the performance, because it determines the optimum amount handled by an industry, and therefore the size of firms in a market. The technical conditions are the main determinant of returns, as well as technical progress.
Yields rise as production differs more significantly than the variation of inputs used. The production of an additional unit is then accompanied by a decrease in unit cost, and the same number of factors capable of producing more. The yields are constant as output varies in the same proportion as factors of production used, the cost also remains constant.
Yields decrease when output varies less than the variation of inputs used. This means that the marginal cost is increasing thus the more costly it is to produce an additional unit. When the returns become negative, this points to waste of scale or diseconomies of scale.
In practice, yields are generally increasing for small quantities, to become constant they decrease for very large quantities. Then there exists an optimum volume for the company, which helps maximize returns.
However, the assumption of constant returns to scale is not always fulfilled. This is the case when the doubling on these efficient factors would be possible. That is, in duplication and more efficient use of input factors, the output would be more than double. This can be triggered by specialization and division of labor (for instance through better utilization of machines). In such a case it points to increasing returns to scale.