问题如下图：
选项：
A. 
B. 
C. 
解释：
老师，这道题目做对了，但是我看了答案和助教老师的讲解，发现自己的理解有一些误区，所以想确定下。
我以为ATC如果保持在15（即不变），才是constant returns to sale，但是讲解说明不是。
所以老师能不能举个例子：是不是ATC = 17 就是规模经济？如果LATC = 15呢？？
NO.PZ2016010801000025 问题如下 Healthy Co. is a factory whiprocing health care procts. The long-run average totcost is $15 per unit antotoutput is 500 units. The manager plans to increase the totoutput to 600 units. After some calculation, it is expecteththe long-run average totcost will increase to $18. Whiof the following scription about Healthy Co. is most appropriate? A.Healthy Co. is experiencing the constant returns to scale. B.Healthy Co. is experiencing the seconomies of scale. C.Healthy Co. is experiencing the economies of scale. B is correct.When the scale of the business increases (600/500-1=20%), the average unit costs increases (18/15-1=20%) well. upwarsloping long-run average totcost curve means seconomies of scale.考点规模经济。解析:产出上涨了600/500-1=20%，平均销售成本也上涨了18/15-1=20%注意到平均单位成本的上涨就意味着企业运行在规模不经济的阶段。 题目说的是计划增产，通过计算如果增产那么单位成本就会增加。也就是当前已经是处于规模经济阶段了，如果按计划增产，就会进入规模不经济啊。不是吗？
NO.PZ2016010801000025 问题如下 Healthy Co. is a factory whiprocing health care procts. The long-run average totcost is $15 per unit antotoutput is 500 units. The manager plans to increase the totoutput to 600 units. After some calculation, it is expecteththe long-run average totcost will increase to $18. Whiof the following scription about Healthy Co. is most appropriate? A.Healthy Co. is experiencing the constant returns to scale. B.Healthy Co. is experiencing the seconomies of scale. C.Healthy Co. is experiencing the economies of scale. B is correct.When the scale of the business increases (600/500-1=20%), the average unit costs increases (18/15-1=20%) well. upwarsloping long-run average totcost curve means seconomies of scale.考点规模经济。解析:产出上涨了600/500-1=20%，平均销售成本也上涨了18/15-1=20%注意到平均单位成本的上涨就意味着企业运行在规模不经济的阶段。 如题
NO.PZ2016010801000025 问题如下 Healthy Co. is a factory whiprocing health care procts. The long-run average totcost is $15 per unit antotoutput is 500 units. The manager plans to increase the totoutput to 600 units. After some calculation, it is expecteththe long-run average totcost will increase to $18. Whiof the following scription about Healthy Co. is most appropriate? A.Healthy Co. is experiencing the constant returns to scale. B.Healthy Co. is experiencing the seconomies of scale. C.Healthy Co. is experiencing the economies of scale. B is correct.When the scale of the business increases (600/500-1=20%), the average unit costs increases (18/15-1=20%) well. upwarsloping long-run average totcost curve means seconomies of scale.考点规模经济。解析:产出上涨了600/500-1=20%，平均销售成本也上涨了18/15-1=20%注意到平均单位成本的上涨就意味着企业运行在规模不经济的阶段。 units从500到600但是他们的成本从15增加到18，那就是slope是上升的，那就是规模不经济啊，还要算吗
NO.PZ2016010801000025 Healthy Co. is experiencing the seconomies of scale. Healthy Co. is experiencing the economies of scale. B is correct. When the scale of the business increases (600/500-1=20%), the average unit costs increases (18/15-1=20%) well. upwarsloping long-run average totcost curve means seconomies of scale. 考点规模经济。 解析:产出上涨了600/500-1=20%，平均销售成本也上涨了18/15-1=20% 注意到平均单位成本的上涨就意味着企业运行在规模不经济的阶段。这道题前面计算了量的20%有用吗？不是直接看单位平均成本，也即是这后一会20%有没有变化就可以了吗？前面这个20%主要是用在哪里？
单位成本都是33.3，500/15,600/18,单位成本不变不应该是规模经济吗
