
WPI: The abbreviation for Wholesale Price Index, which is an index of the prices paid by retail stores for the products they would ultimately resell to consumers. The Wholesale Price Index, abbreviated WPI, was the forerunner of the modern Producer Price Index (PPI). The WPI was first published in 1902, and was one of the more important economic indicators available to policy makers until it was replaced by the PPI in 1978. The change to Producer Price Index in 1978 reflected, as much as a name change, a change in focus of this index away from the limited wholesalertoretailer transaction to encompass all stages of production. While the WPI is no longer available, the family of producer price indexes provides a close counterpart in the Finished Goods Price Index.
Visit the GLOSS*arama




AVERAGEMARGINAL RELATION: A mathematical connection between a marginal value and the corresponding average value stating that the change in the average value depends on a comparison between the average and the marginal. This mathematical relation between average and marginal surfaces throughout the study of economics, especially production (average product and marginal product), cost (average total cost and marginal cost), and revenue (average revenue and marginal revenue). A similar relation is that between a total value and the corresponding marginal value. The mathematical relation between average and marginal means that the average value is "driven" by the marginal value.  If the marginal is less than the average, then the average declines.
 If the marginal is greater than the average, then the average rises.
 If the marginal is equal to the average, then the average does not change.
The reason for this relation is that average value is based on the existing situation that is then modified by the marginal value. This averagemarginal relation applies to average and marginal product, average and marginal cost, average and marginal revenue, and well, any other average and marginal encountered in the study of economics.To illustrate the basic nature of the averagemarginal relation consider an example. Suppose that there is a room containing five people that have been painstakingly and accurately measured for height. The average height of this group is 66 inches (5' 6"). Some are taller than 5' 6" and some are shorter, but the average is 5' 6". What happens to this 5' 6" average should a sixth person enter the room? This surely depends on the height of this extra person, this marginal addition to this group, does it not?  If this "marginal" person is 6' tall, then the group's average rises to exactly 5' 7". The marginal is greater than the average, and the average rises.
 If the marginal sixth person is, however, a mere 5' tall, the marginal is less than the average, then the average declines to 5' 5".
 And if the new, marginal person, is exactly 5' 6'', the same as the existing average, then the average does not change.
Average and Marginal Product 

 This averagemarginal relation can be graphically illustrated, using the average product and marginal product curves displayed to the right. A comparison between average product and marginal product reveals three alternatives. When the marginal measure is greater than the average measure (that is, the marginal product curve lies above the average product curve), then the average measure increases (and the average product curve has a positive slope).
 Alternatively, when the marginal measure is less than the average measure (that is, the marginal product curve lies below the average product curve), then the average measure decreases (and the average product curve has a negative slope).
 In addition, when the marginal measure is equal to the average measure (that is, the marginal product curve intersects the average product curve), then the average measure does not change (and the average product curve has a zero slope).
Recommended Citation:AVERAGEMARGINAL RELATION, AmosWEB Encyclonomic WEB*pedia, http://www.AmosWEB.com, AmosWEB LLC, 20002024. [Accessed: March 5, 2024]. Check Out These Related Terms...         Or For A Little Background...       And For Further Study...         
Search Again?
Back to the WEB*pedia



WHITE GULLIBON [What's This?]
Today, you are likely to spend a great deal of time searching for a specialty store looking to buy either a toaster oven that has convection cooking or a birthday gift for your mother. Be on the lookout for doortodoor salesmen. Your Complete Scope
This isn't me! What am I?


The earliest known use of paper currency was about 1270 in China during the rule of Kubla Khan.


"All things are difficult before they are easy."  Thomas Fuller, Physician


JEMS Journal of Economics and Management Strategy


Tell us what you think about AmosWEB. Like what you see? Have suggestions for improvements? Let us know. Click the User Feedback link.
User Feedback

