diminishing returns

A curve of output against input. The areas of increasing, diminishing and negative returns are identified at points along the curve. There is also a point of maximum yield which is the point on the curve where producing another unit of output becomes inefficient and unproductive.

In economics, diminishing returns means the decrease in marginal (incremental) output of a production process as the amount of a single factor of production is incrementally increased, holding all other factors of production equal (ceteris paribus). The law of diminishing returns (also known as the law of diminishing marginal productivity) states that in a productive process, if a factor of production continues to increase, while holding all other production factors constant, at some point a further incremental unit of input will return a lower amount of output. The law of diminishing returns does not imply a decrease in overall production capabilities; rather, it defines a point on a production curve at which producing an additional unit of output will result in a lower profit. Under diminishing returns, output remains positive, but productivity and efficiency decrease.