ELASTICITY...

If you know who she is, then you would know that she loves elasticity ;)

Price elasticity is the measure of response of the people to changes in economic variables. For example price elastic in demand means that if there is a price increase, then the demand for that particular good decreases. This is due to the fact that there are substitutes present.

An excellent example would be buying different brands of toothpaste.

Toothpaste. =)

 If price of Colgate increases, then people would start buying other brands like Darlie.

BAD COLGATE, BADDD!!!

This man bought Darlie instead of Colgate. =(

Price inelastic of demand on the other hand means that if prices increase, there would be very little change in demand. For price inelastic products, substitutes are very limited or there are no substitutes at all. Another reason would be because it is a necessity good. Reasons would be like the increase in the price of petrol. If Shell and Petronas decides to increase their price of petrol, we would still purchase it because there are no other substitutes unless you buy a hybrid car, which also needs some amount of petrol. 

OMG T__T

Consumers are disappointed :(

HAHAHAHA HYBRID CARSS.

There are also unit elastic , perfectly elastic and perfectly inelastic of demand. Basically, what unit elastic means is that a change in the price would have the same change in demand, for example if the price increases one ringgit, then the good will decrease one unit, causing revenues to be unchanged. Perfectly elastic of demand just means that if prices increase, the demand of the product would be zero because the buyers are sensitive to the change in price. Lastly, the perfectly inelastic of demand means that the increase in price would have a zero effect in the change in demand. 

Perfectly elastic graph

Perfectly inelastic graph.

http://www.extension.iastate.edu/agdm/wholefarm/pdf/c5-207.pdf