Question

In a perfectly competitive market, what happens when market demand increases in the long run?

Are there fewer or more firms?

Does price go up, down, or stay about the same?

Answer 1

In perfectly competitive market, if market demand increases in the long run it will cause demand curve to shift right which means that in short run at the same price Quantity demand is more than quantity supply. This will put upward pressure on price. The increase in price cause supply to increase and some of quantity demand to decrease until the new equilibrium at higher price and higher quantity will achieve.

The rise in price cause more firms to enter into the market.

So,

There will be more firms in the market.

Price goes up or increases.