长期有时被定义为没有沉没固定成本的时间范围。一般而言，固定成本是指随着生产数量的变化而变化的成本。此外，沉没成本是指在支付后无法收回的成本。例如，如果企业必须为办公空间签订租约，则租赁公司总部将是沉没成本。此外，这将是固定成本，因为在确定运营规模后，公司不会为其生产的每个额外输出单元需要一些增量额外的总部单位。显然，如果公司决定进行重大扩张，公司将需要更大的总部，但这种情况是指选择生产规模的长期决策。从长远来看，没有真正的固定成本，因为公司可以自由选择决定成本固定水平的运营规模。此外，从长远来看，没有沉没成本，因为公司可以选择不做生意并且成本为零。
英国埃塞克斯大学论文代写：长期决策
Long-term is sometimes defined as a time frame that does not sink a fixed cost. In general, fixed costs refer to costs that vary with the amount of production. In addition, sunk costs refer to costs that cannot be recovered after payment. For example, if a company has to sign a lease for office space, the rental company headquarters will be a sunk cost. In addition, this will be a fixed cost, because after determining the scale of operations, the company will not need some incremental additional headquarters units for each additional output unit it produces. Obviously, if the company decides to make major expansions, the company will need a larger headquarters, but this is a long-term decision to choose a production scale. In the long run, there is no real fixed cost, because the company is free to choose the scale of operations that determine a fixed level of cost. In addition, in the long run, there is no sunk cost because the company can choose not to do business and the cost is zero.