There are many categories of costs that economists use to explain the true costs to a firm. A firm's economic costs (implicit and explicit) reflect the opportunity costs of its production process. It is critical that you understand the difference between accounting and economic costs. It is also important to be able to define each type of cost, calculate the costs and graph a firm's different types of production costs. The costs are assumed to be the same for all firms in all four of the market structures. The firm's costs are used when analyzing a firms profit maximizing behavior. Good economic thinking