The Supply Curve

On the left we see a supply curve.

As you can see, the supply curve goes up from left to right.

OK so far?



But.....

As the price rises, there will come a time when a lot of firms join the industry. Surely then the supply curve would flatten out?

Also, as production incrases, firms will get economies of scale - so surely the supply curve will shift to the right?

Thoughts...

Supply Curve

If the price a consumer is willing to pay rises, then the supply curve extends. If more firms join the market (because the price has risen therefore making the profits larger) the supply curve extends - or does it shift?

If, as a firm produces more, it gets economies of scale, then the average costs fall so is that an extension or a shift in supply?
If the supply curve shifts outwards then the prices fall - so won't supply contract?