Ten Principles of Economics - Part 28. Economics is the study of how society manages its scarce resources. In most societies, resources are allocated not by a single central planner but through the combined actions of millions of households and firms. Economists therefore study how people make decisions: how much they work, what they buy, how much they save, and how they invest their savings. Economists also study how people interact with one another. | CHAPTER 13 THE COSTS OF PRODUCTION 281 production process the second or third worker might have higher marginal product than the first because a team of workers can divide tasks and work more productively than a single worker. Such firms would first experience increasing marginal product for a while before diminishing marginal product sets in. Table 13-3 shows the cost data for such a firm called Big Bob s Bagel Bin. These data are graphed in Figure 13-6. Panel a shows how total cost TC depends on the quantity produced and panel b shows average total cost ATC average fixed cost AFC average variable cost AVC and marginal cost MC . In the range of output from 0 to 4 bagels per hour the firm experiences increasing marginal product and the marginal-cost curve falls. After 5 bagels per hour the firm starts to experience diminishing marginal product and the marginal-cost curve starts to rise. This combination of increasing then diminishing marginal product also makes the average-variable-cost curve U-shaped. Despite these differences from our previous example Big Bob s cost curves share the three properties that are most important to remember Marginal cost eventually rises with the quantity of output. The average-total-cost curve is U-shaped. The marginal-cost curve crosses the average-total-cost curve at the minimum of average total cost. Quantity of Bagels per hour Total Cost Fixed Cost Variable Cost Average Fixed Cost Average Variable Cost Average Total Cost Marginal Cost 0 1 2 3 4 5 6 7 8 9 10 11 12 13 .
