3.4.2 The Cost Structure of Aluminum Plants So let's take another look at the costs, and see which costs are fixed and which are variable. Drag each of the costs listed below to its correct category. And, here's a key point: notice that some of the costs that we're labeling as "fixed" here may be variable in other settings. Consider labor costs: sometimes, as at these three plants, relatively strict labor laws might force you to keep a full contingent of workers, regardless of plant conditions. At other times, or at other plants, you might have more flexibility to hire or layoff workers as conditions change. In other words, whether a cost is fixed or variable depends not only on the "type" of cost but also on things like regulations, market characteristics, social norms, and so on