Price Elasticity of Supply, HELP!?

Eroticplants

So I'm a first year business student and have my microeconomics exam on Monday, elasticity is coming up fo sho and I don't understand:

The the determinants of PES, The Time Period.
How in the short run PES tends to be inelastic and in the long run tends to be elastic.

Anyone out there able to explain in the most simplistic terms possible??

Économiste Monétaire

Well, the PES measures how responsive supply is to a change in price, so you're focusing on the supply side of the market, here.

Imagine you're a potato farmer, and the upward sloping supply curve holds true for you. Price increases by, say, 10%: how should you respond to this? Textbook answer: by increasing the quantity of potatoes supplied. But, in the short-run, you can't magic up new potatoes overnight, you need to invest in more land, machinery, hire workers, and so on, so you might not be able to increase supply a lot, even with an increase in price.

This is just applying the concept of short-run fixed factors of production, which makes PES inelastic, and in the long-run all factors should be free, so PES is relatively more elastic because you can better respond to a change in price. The agricultural case above is usually used an example the extreme situation of near perfectly inelastic PES.

Eroticplants

Thank you!

I thought I'd never understand it!