
WANTS AND NEEDS: These are the unfulfilled desires that motivate human behavior and that when satisfied improve human wellbeing. They include both physiological or biological requirements for maintaining life (needs) and the psychological desires which make life more enjoyable (wants). However, when push comes to shove, and the nitty gets down to the gritty, it matters very little to markets if people need goods or want goods, so long as they are motivated to buy the goods to satisfy wants and needs.
Visit the GLOSS*arama




ARC ELASTICITY: The average elasticity for discrete changes in two variables. The distinguishing characteristic of arc elasticity is that percentage changes are calculated based on the average of initial and ending values of each variable, rather than initial values. Arc elasticity is generally calculated using the midpoint elasticity formula. The contrast to arc elasticity is point elasticity. For infinitesimally small changes in two variables, arc elasticity is the same as point elasticity. Arc elasticity is best considered the average elasticity over a range of values for a relation. Like any average, some values within the range are likely to be greater and some less. However, it provides a quick approximation of elasticity when more precise and sophisticated calculation techniques are not possible.Working Through an ExampleA Standard Demand Curve 

 The demand curve displayed to the right can be used to illustrate the measurement of arc elasticity using the midpoint elasticity formula. If the price declines from $12 to $8, the quantity demanded increases from 4 to 6, from point X to point Z. Using this midpoint formula (with price designated as P and quantity designated as Q) average price elasticity of demand is:midpoint elasticity  =  (Q[Z]  Q[X]) (Q[Z] + Q[X])/2  ÷  (P[Z]  P[X]) (P[Z] + P[X])/2 
midpoint elasticity  =  (6  4) (6 + 4)/2  ÷  (8  12) (8 + 12)/2  =  (2) (5)  ÷  (4) (10) 
midpoint elasticity  =  0.4  ÷  0.4  =  1.0 
Ignoring the minus sign, the price elasticity of demand over this segment of the demand curve from X to Z is 1.0.An Average ValueThis value of 1.0 is actually an average for the entire range between points X and Z. Precise estimates of point elasticity shows that the elasticity is 0.67 at point X and 1.5 at point Z. Moreover, the elasticity is different at each point on a straight line demand curve such as this one. The only point in which the elasticity is exactly equal to 1.0 is at point Y, the midpoint between X and Z.This last observation is worth emphasizing. The midpoint elasticity formula effectively estimates the point elasticity at the very midpoint of the overall segment. This means that the elasticity of any point on a demand curve (point elasticity) can be obtained by calculating the arc elasticity with the midpoint elasticity formula such that the desired point is dead center in the middle, the midpoint of the arc.
Recommended Citation:ARC ELASTICITY, AmosWEB Encyclonomic WEB*pedia, http://www.AmosWEB.com, AmosWEB LLC, 20002024. [Accessed: November 14, 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 watching infomercials hoping to buy either a computer that can play video games and burn DVDs or a black duffle bag with velcro closures. Be on the lookout for florescent light bulbs that hum folk songs from the sixties. Your Complete Scope
This isn't me! What am I?


Rosemary, long associated with remembrance, was worn as wreaths by students in ancient Greece during exams.


"Do something wonderful; people may imitate it. "  Albert Schweitzer, theologian, physician


SSAP Statement of Standard Accounting Practice


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

