In the short run, Alex will shut down his lawn-mowing service rather than continue with it if the total revenues would not be able to cover the total variable costs he has. A perfectly competitive industry is a market structure where all the firms in the market sells the same product, the firms cannot control the prices of the product, they have a small share in the market, the consumers know all of the information about the product and the products would have a freedom of entry and exit. Most likely, firms in that certain industry would be able to sell well depending on how they would advertise and market their product.