Simplify the following text for a Grade 9 native English-speaking person.
Original: The basic definition of the word is at elastic In economics , people talk about elasticity of supply , or demand , or of price .
Simplified: The price elasticity of supply measures how the amount of a good firms wish to supply changes in response to a change in price . In a manner analogous to the price elasticity of demand , it captures the extent of movement along the supply curve .