2010年4月，国务院常务会做出决定，为了深化能源价格改革，加强能源需求管理，将推行居民用电阶梯价格。2010年10月，电价主管部门国家发改委发布了《居民阶梯定价指导意见（征求意见稿）》，推出了实施阶梯定价的两个选择方案。阶梯定价方案公布后，立刻引起了公众的广泛关注，这当然与其彰显的涨价因素有关。毕竟，居民用电是一个重要的民生问题。不过，涨价仅仅是故事的一部分，在通胀来临时，涨价并不是新闻，不涨价才是新闻。除涨价之外，这次电价改革更值得关注的，也许是从线性定价到阶梯定价这种定价方式的转变。实际上，在世界各国的电价实践中，阶梯定价并不是什么新鲜事物。早在20世纪70年代，为了解决电价上涨对低收入用户的冲击，美国一些地方就引入了累进的阶梯定价时代。近年来，随着全球对环境和可持续发展问题的关注，很多国家的管制机构又重新燃起对阶梯定价的热情，纷纷引入这种定价方式。但是，毋庸讳言，自打阶梯定价诞生之日起，无论是为了调节收入分配，还是旨在促进资源节约，都掩盖不了与效率原则存在的明显冲突。正是阶梯定价与资源配置效率的这种内在矛盾，决定了在选择这种定价方式时必须反思其基本逻辑。一 涨价的艺术按照国家发改委的解释，在居民阶梯电价的三个档次中，第一档电量按满足居民基本用电需求确定，电价维持较低价格水平；第二档电量反映正常合理用电需求，电价逐步调整到能弥补电力企业合理成本加合理收益的水平；第三档电量体现较高生活质量用电需求。两个方案的具体情况是：对于方案1，第一档按照电量覆盖70%计算，每户每月用电量在110千瓦时以下时，维持现有电价，并且今后三年不变；第二档按照电量覆盖90%设计，每户每月用电量在110—210千瓦时时，超出基本用电量部分，每千瓦时电上涨5分钱；第三档，每户每月用电量超过210千瓦时，超出部分每千瓦时电上涨2毛钱。对于方案2，第一档按照电量覆盖80%计算，每户月用电量低于140千瓦时时，每千瓦时上涨1分钱；第二档按照电量覆盖95%设计，每户每月用电量在140—270千瓦时时，超出部分每千瓦时电上涨5分钱；第三档，每户每月用电量超过270千瓦时时，每千瓦时电上涨2毛钱。通过简单比较后可以看出，在这两个阶梯定价方案中，除方案1中第一档电量的用户电价维持在现有水平不变以外，其他用户的电价都将面临上涨，这意味着此次电价调整将提高整体电价水平。对于为什么涨价，按照国家发改委给出的解释，同时也是发电企业的普遍抱怨，是目前的居民用电价格过低，甚至使发电企业处于亏损的边缘。由于居民供电的电压低，居民供电成本本来就高，再加上近年来煤炭价格上涨很快，而煤电价格联动机制却没有建立起来，由市场决定的煤价上涨了，但电价仍被人为地限制在较低的水平，所以，需要让电价回归理性。无论是国家发改委的解释，还是发电企业的抱怨，显然都是一种垄断叙事，很难赢得普通百姓的认可，这很容易理解，因为在现有的电力体制下，发电企业的发电成本缺乏竞争约束，上网电价也不是在竞争中形成的，所以，谈论电价低或者供电成本高都没有实质意义。当然，引入电力市场竞争机制，并不意味着电价必然会降低，而不过是说，竞争机制会增加成本信息和价格形成的可信性，这是问题的本质所在。定价问题的背后其实是电力体制问题，也是电力市场机制问题。但现在的情况是，虽然发电生产已经市场化，但是，销售还没有市场化，电力批发市场尚未建立起来，上网电价还是由国家控制，电力销售还在国家的控制下，由电网公司在统购统销。2002年国务院5号文件明确电力市场化改革方向以来，电力改革可以说是进展缓慢，其根本原因在于缺乏改革的动力。希克斯说过，垄断的最大好处是可以享受悠闲的生活，也就是说，凭借垄断地位赚钱太容易了。推进电力市场化改革，就意味着要触动很多人的利益，就会存在巨大的阻力。在电力市场化改革难以推进时，就会依赖现有的电价形成机制，通过涨价来解决很多矛盾。但是，涨价无疑会产生巨大的张力，这一点政府部门无疑是非常清楚的。这次电价改革很有意思的一个地方是，相关部门很聪明，他们知道，简单地按照原来的定价方式涨价，老百姓的意见肯定会非常大，会影响政府的形象，所以，在涨价的同时，突出了节约资源的主题，因为富有的人一般会消耗更多的电力，因此，在定价方案中，让这些人支付更高的电价。这样，涨价就占据了道德的制高点，看起来很美。实际上，这次涨价的一个主要特点是，价格调整方案隐含了一个收入再分配的思想，这样给人的感觉是，涨价本身是在追求公平正义，价值理性的言说消弭了很多人的对抗情绪。但是，很显然，阶梯定价本身并没有解决电力价格形成机制问题，本质上讲，阶梯定价无非是给出了一个美妙的涨价理由。甚至阶梯定价改革反映出当前改革出现的一些苗头，那就是泛价值论取代了工具理性。二 收入分配叙事赋予阶梯定价调节收入分配功能，说明政府认识到民众对现阶段收入分配状况的不满，也反映了财政税收这种传统的收入分配调价方式存在很多问题。但是，即使把阶梯定价作为调节收入再分配的工具，或者说把电力消费作为实物再分配手段，仍需要考量它是不是最有效的方式。此次推出的阶梯定价的最基本特点是，随着用电量的上升，适用的边际价格是累积递增的。按照最基本的经济学常识，这种定价方式违背了电力成本规律，因为电力生产的长期增量成本，包括可变成本、专属的固定成本和容量成本，并不随用电量的增加而改变。能够更好地反映这种成本结构的是二部制定价，或者实时定价，而不是阶梯定价。缺乏成本基础的阶梯定价，无疑是违背有效经济原则的，会产生无谓的福利损失。在考虑是否用扭曲相对价格手段实现收入分配目标时，经济学中有一个非常著名的原理，叫作阿科森—斯蒂格利茨定理，这是任何领域政府定价都必须首先考虑的一个基本原则。它的主要意思是，在一般条件下，收入分配不需要扭曲价格，只需借助税收手段就可以了，用价格手段调整收入分配，注定是缺乏效率的。价格就是价格，其目的很简单，就是作为资源配置的信号，它不能做其他的事情，包括不能用来调节收入分配。若用价格手段调节收入分配，必然要付出资源配置效率的代价。当然，现实世界是复杂的，不一定满足阿科森—斯蒂格利茨定理的条件，因此，存在用价格手段调节收入分配的空间。本质上讲，用价格手段改善收入分配的理性，取决于价格扭曲所产生的福利损失与税收系统效率的比较结果。这里要用到一个重要概念，叫作公共资金的边际成本，简单地讲，其含义是每收取一元税收所产生的社会成本。一般来说，发达国家的税收体系效率较高，因此采用财政税收手段更为合理；而发展中国家的财政税收体系效率较低，公共资金成本更高，运用价格手段的空间更大。即便如此，也要具体考量价格扭曲带来的福利损失，最好采用旨在针对特定群体的调节方式。在现实生活中，用价格手段改善收入分配产生的一个危险是，收入分配目标常常被作为保护垄断的借口，这是因为，扭曲的价格，包括阶梯定价，与竞争机制格格不入，只有在垄断体制下，依靠强制力量，这种机制才能得以实施，从这个意义上讲，阶梯定价包含着垄断思维。现在，很多行业都提出普遍服务目标，就是给所有人都提供服务，不管其服务成本或支付能力如何，但问题是提供这些服务可能是亏本的，比如说高原或边远地区，收入水平比较低的用户，在没有政府直接补贴的情况下，提供服务需要交叉补贴，这种交叉补贴机制最后就演变成垄断的借口。必须强调的是，阶梯定价不符合消费者的激励相容约束，因此无法给予消费者选择权。也就是说，给予消费者不同的边际价格选择，大家肯定会选择较低的价格，因此阶梯定价只能靠强制力来实施。与此相对的是，在电信领域，消费者已经有电信资费选择权，在垄断体制下，是不可能有这样的选择权的。除效率问题外，通过扭曲价格改善收入分配还涉及程序正义问题，这个问题与“价”和“税”的混搭有关。按照国家发改委的解释，预计涨价后多收的钱中，一部分补贴电厂成本的提高，另一部分是补贴脱硫成本，这正是内部化了的部分外部成本。当然，还有尚未内部化的外部成本。由此来看，阶梯定价有三重使命：一是回收电力成本；二是将电力使用的外部成本内部化，也就是征收“庇古税”，相当于用户消费电力后，除支付直接成本外，还要支付环境成本；三是调节收入分配。在阶梯定价中，既有价的含义，又有税的概念，但问题是，“价”和“税”是混在一起的，对于消费者来讲，只知道与个人所得税一样，阶梯定价是一种累进税，但不知道哪部分是付出的价格，哪部分付出的是“庇古税”，哪部分属于实物收入分配。当然，这种现象并不只是在电力定价中存在，价和税混为一谈实际上是一种常态，一般的老百姓根本就不知道自己的纳税行为。居民用电对消耗资源的社会成本，和用电多少到底是个什么关系，并不是显而易见的。显然，不能简单地说，用电多，边际成本就高。虽然累进的庇古税有调整收入分配的功能，但是，从定价角度看并不合理，更不要说有关部门连电力生产成本和环境成本都没有测算。即使是电力行业作为一个特殊行业，在使用环节增收庇古税有其逻辑基础，那也要把价和税分开，让价和税透明，这样，也有利于公民社会的建立，让老百姓清楚自己的纳税义务，同时使政府对收上来的钱负责，这是定价和征税的程序正义的要求。但政府现在的做法是，只解释了涨价后的钱用来干什么，就是以将来的用来定现在的收，而没有提供价和税的透明性，因此给人的感觉就是为了涨价。三 资源节约命题的困境通过征收庇古税，使用户承担用电的全部社会成本，意在节约能源，保护环境。但是，节约能源并不是简单的一个命题，即使提高电价能降低用电量，也不意味着能源消费的减少，节约能源的命题需要在更大的范围内进行考量。调高电价，能够降低电力需求，从而能节约能源，这里面有一个假设，就是消费者会因为付费更高，而降低整体的能源需求。这个假设并不一定成立，因为消费者并不一定因为电价的上升，就减少了对能源的整体需求，很可能转用其他的替代性能源。资源节约命题的复杂之处，在于居民电力需求并不是最终需求，而是一种其他消费所引致的需求，也就是说，人们需要的不是电力本身，而是使用电力做其他事情。问题在于，能源的种类很多，并且是可以相互替代的，用经济学语言说，就是提高电价不仅产生收入效应，因而会抑制电力需求，还会产生替代效应，而替代方式和替代程度取决于短期和长期的考量。比如，做饭可以用电，也可以用天然气，当电价提高以后，人们会更多地使用天然气，满足做饭的需求。另外，改变电价可能会改变人们的生活方式，但不一定会改变人们的能源需求。比如电价很低时，很多人习惯用电脑在网上阅读，但如果电价上涨了，就很可能改为打印出来阅读。用电虽然少了，但是用纸多了，哪种方式能节约能源，哪种方式对环境更友好？前一阶段，很多人讨论电动车是否节约能源，或者说是否更环境友好。从电动车取代开车的方式来看，电动车将减少汽油消耗，因此确实节约了能源，但是，电动车是要充电的，并且需要回收处理电池，而充电电池对环境的潜在影响可能难以估量，很多专家甚至认为，从长远来看，它产生的污染远远高于汽油的使用。从电力本身的特点来看，电力是二次能源，相比于一次能源，它本身就是一种高效清洁能源，这也是国家为什么大力发展电力、为什么花那么多的钱来修建输电网络的原因。如果电价上涨，而其他的能源价格不变，人们就会选择替代能源，或者说替代的生活方式，因此涨价能否达到能源需求减少的效果很难说。如果民众能源的需求总量不变，那么用效率更低、对环境更不友好的能源来代替电力，显然是得不偿失的。从根本上讲，资源的消耗取决于增长方式，更确切地讲，就是经济发展速度。不可否认的是，目前的全球资源定价难以反映全部成本，并且一些主要环境污染物如二氧化碳具有全球公共品属性，在这种条件下，经济增长实际上是“搭便车”行为，转变增长方式是难以承诺的政治意愿，在缺乏全球性约束机制的情况下，任何一个政府都很难约束增长的冲动。由此来看，仅仅通过提高电力价格，而不是彻底改变增长方式，降低发展速度来调整能源需求，是不大现实的。四 阶梯定价的挑战如果引入阶梯定价是一种政治选择，那么不管是让电价回归理性，还是调节收入分配，或者是促进能源节约，实现这些美好的意愿，都需要制定和实施合理的阶梯价格，但是，因为阶梯定价本身的一些属性，采用这种定价方式面临着巨大的挑战。对此，无论是学术界还是价格主管部门，都要有足够的认识，否则就会难以达到其效果。根据微观经济学基本原理，对于累积性的阶梯定价，有两个问题特别值得关注：一是不同档电价的相互影响。在存在多档电价的情况下，阶梯电价的一个重要性质是，低档电价对高档电价消费者产生纯粹的收入效应，但没有替代效应，也就是说，提高适用于低收入消费者的低档电价会更有效地抑制电力消费，这是阶梯定价的一个悖论。这个悖论意味着，在电价水平和改变消费行为之间，方案1和方案2存在一个无奈的权衡：方案2的低档电价高于方案1的低档电价，但由于超边际价格产生的收入效应，尽管方案1和方案2的高档电价水平相同，但在方案2下，不仅低档电量消费者会减少消费，而且相对于方案1而言，高档电量用户也会减少电力消费。二是在阶梯定价的拐点存在用电消费的集聚，也就是说，很多具有不同偏好的消费者，会选择彼此相同的处于拐点的电力消费水平。这就等于说，阶梯定价可能会减少，而不是增加需求效应，这显然与有效电力定价原则相违背，这是阶梯定价的另一个悖论。递增阶梯定价的这个重要特征，将影响不同档电价水平的选择，以及不同档拐点的确定。从目前来看，难以知晓相关部门是否关注到这种转变定价方式带来的技术问题。但需要强调的是，这些考虑并不仅仅是纯技术上的，在阶梯定价时代，这些看起来有些难以理解的技术问题，意味着价格主管部门必须面临非线性定价带来的技术挑战，特别是反映在微观信息的需求上。在线性定价时代，制定最优定价并不需要考虑消费者的偏好信息，只需要知道加总的需求信息就可以了，因为只要有电力总需求的弹性信息和成本信息，就可以按照拉姆齐定价原则确定最优电价。但是，作为一种非线性定价，阶梯定价彻底改变了信息需求，采用阶梯定价意味着，制定最优价格仅仅了解总需求是不够的，还需要了解个体需求信息。这对习惯于线性定价的价格主管部门，无疑是方法论的革命。当然，从实际操作来看，这种理性诉求也许过于苛刻，政府定价可能不会太关注这种工具理性要求，或者只能满足部分理性要求。比如，由于种种原因，阶梯定价的拐点可能由政治决定，价格主管部门的政策工具变成只是对不同档的电价进行优化，在这种情况下，过去的线性定价思维也许仍在一定程度上适用。不过，按照目前的信息，无从判断不同档电价水平的理性程度，对于拐点的确定，国家发改委提出由各地方自己决定，但无法知道确定这些拐点的准则。必须指出的是，不采用有效定价也许不影响阶梯定价的政治正确性，也不会影响阶梯定价的实施，但政府和公众必须认识到，由此带来的机会成本是巨大的，这种机会成本虽然是隐含的，但是，和直接减少消费者福利的任何方式，比如减少消费者的收入，或者减少消费者的消费满足，并没有本质区别。阶梯定价带来的另一个挑战，将会反映在实施后对其效果的评估上。可以预计，实施阶梯定价后，无论是政府部门还是学术界，为了评估阶梯定价的实施效果，或者是出于改善阶梯定价的目的，都需要对阶梯定价效果进行实证研究，比如估计相关的弹性。但是，在阶梯定价下，这些实证研究面临着很大的挑战，包括需要更多地了解家庭层面的微观信息，而且面临着一系列技术难题，比如，如何考虑边际价格和平均价格的影响。如果不能合理地考虑这些问题，将会误导未来的定价政策。五 电价改革的未来前面的分析表明，阶梯定价充其量只是一种调节收入分配的手段，但是，远没有解决电价最为核心的问题，即促进电力行业资源的有效配置。那么什么是电力行业的有效定价呢？答案在于实时定价。电力行业最基本的技术经济特征是，电力系统的潜在需求和供给可能是不平衡的，但电力系统又必须时刻维持平衡。给定任何一个时点，如果电力需求不足，电力供应过剩，就需要电力供应系统减少发电和输电量，否则电力系统就会出问题，比如保险丝会熔断，电器会被毁坏；如果需求过剩，现有的容量不足，电力系统同样会出问题，比如灯泡会暗下来。由于电力需求存在不确定性，而发电和输电容量的增加是非连续的，并且需要付出成本，因此电力系统的永恒主题是，如何在短期内，在容量有限的情况下进行需求管理；在长期意义上，促进容量的合理增加。电力产品的这种特征，决定了电力行业的定价与一般产品的定价是不同的，电力的最优定价必须与特定的时空相联系。发电行业的有效定价需要解决的问题，与其他具有容量限制的行业，比如交通行业是非常类似的。对交通行业而言，供给和需求往往是不匹配的。比如，在早高峰或晚高峰时期，路网非常拥挤，满足不了车辆的需求，但除此之外的绝大部分时间，并没有那么多的车，路网在很大程度上处于利用不足的状态。越来越多的道路拥堵问题，并不仅仅在于道路的建设跟不上车辆的增加，在一定的时间内，供给确实是有限的，道路不可能一下子增加，因为修一条路不仅需要资金，还需要一定的建设时间，更重要的是，保持一定的堵塞是符合效率原则的。电力系统也是如此，在用电高峰时，供给难以满足全部需求，因此需要进行需求管理，甚至要拉闸限电，但在大部分时间内，供给是过剩的。电力行业的技术经济特点决定了有效配置电力资源的定价方式是实时定价。在实时定价中，一种最简单的定价方式是峰谷定价，就是在用电高峰时段，用电价格较高；而在用电低谷阶段，用电价格较低，从而使消费者有激励地选择避开峰谷时期用电。实施实时定价是国际上电价改革的主要趋势。在技术上，实施峰谷电价，甚至更复杂的实时定价都不成问题，就是装一个智能电表，将不同时段的电力消费区别开来。其实，中国很早就试图这么做了，但至今没有大规模铺开，这里面有很多原因，最主要的原因是和我们的体制有关。在现有的垄断体制下，企业没有动力这么做，它们当然喜欢用最简单的方式赚钱。对于未来的电价改革，在引入阶梯定价的框架下，仍存在巨大的改革空间。可以考虑的选择是，在阶梯定价中嵌入实时定价（峰谷定价），这样就可以用不同的手段实现不同的目标，其中，峰谷定价主要承担有效定价的使命，而阶梯定价更多地承担社会调节功能，这也许是下一步电价改革可以努力的方向。但这一切都依赖利益相关者所具有的改革动力。张昕竹2015年6月

In April 2010, the executive meeting of the State Council decided that in order to deepen the reform of energy prices and strengthen the management of energy demand, the tiered price of residential electricity will be implemented. In October 2010, the National Development and Reform Commission, the electricity pricing authority, issued the Guiding Opinions on Tiered Pricing for Residents (Draft for Comments), which introduced two options for implementing tiered pricing. After the announcement of the tiered pricing plan, it immediately attracted widespread public attention, which is of course related to the price increase factors highlighted by it. After all, residents' electricity use is an important livelihood issue. However, price increases are only part of the story, and when inflation comes, price increases are not news, and not raising prices is news. In addition to the price increase, what deserves more attention this electricity price reform may be the shift from linear pricing to tiered pricing. In fact, in the practice of electricity pricing in countries around the world, ladder pricing is not a new thing. As early as the 70s of the 20th century, in order to solve the impact of rising electricity prices on low-income users, some places in the United States introduced a progressive era of ladder pricing. In recent years, with the global concern for environmental and sustainable development issues, regulatory agencies in many countries have rekindled their enthusiasm for tiered pricing and introduced this pricing method. However, it goes without saying that since the birth of tiered pricing, whether it is to regulate income distribution or to promote resource conservation, it cannot hide the obvious conflict with the principle of efficiency. It is this inherent contradiction between ladder pricing and resource allocation efficiency that determines that the basic logic must be rethought when choosing this pricing method. According to the explanation of the National Development and Reform Commission, among the three grades of residential tiered electricity prices, the first level of electricity is determined to meet the basic electricity needs of residents, and the electricity price remains at a low price level; The second tranche reflects the normal and reasonable demand for electricity, and the electricity price is gradually adjusted to a level that can make up for the reasonable costs and reasonable benefits of power enterprises; The third gear reflects the higher quality of life electricity demand. The specific situation of the two schemes is: for option 1, the first tranche is calculated according to the electricity coverage of 70%, and when the monthly electricity consumption of each household is below 110 kWh, the current electricity price will be maintained, and it will remain unchanged for the next three years; The second gear is designed according to the power coverage of 90%, and the monthly electricity consumption of each household is 110-210 kWh, exceeding the basic electricity consumption, and the electricity per kWh rises by 5 cents; In the third gear, the monthly electricity consumption of each household exceeded 210 kWh, and the excess increased by 2 cents per kWh. For plan 2, the first tranche is calculated according to the electricity coverage of 80%, and the monthly electricity consumption of each household is less than 140 kWh, which increases by 1 cent per kWh; The second gear is designed according to the power coverage of 95%, and the monthly electricity consumption of each household is 140-270 kWh, and the excess electricity per kWh rises by 5 cents; In the third gear, the monthly electricity consumption of each household exceeded 270 kWh, and the electricity per kWh increased by 2 cents. After a simple comparison, it can be seen that in the two tiered pricing schemes, except for the user electricity price of the first tranche in scheme 1, which remains unchanged at the current level, the electricity price of other users will face an increase, which means that this price adjustment will increase the overall electricity price level. As for why the price has increased, according to the explanation given by the National Development and Reform Commission, and also a common complaint of power generation companies, the current residential electricity price is too low, and even puts power generation enterprises on the verge of loss. Due to the low voltage of residential power supply, the cost of residential power supply is already high, coupled with the rapid rise in coal prices in recent years, but the coal power price linkage mechanism has not been established, the coal price determined by the market has risen, but the electricity price is still artificially limited to a low level, so it is necessary to return the electricity price to rationality. Whether it is the explanation of the National Development and Reform Commission or the complaint of power generation enterprises, it is obviously a monopoly narrative, and it is difficult to win the recognition of ordinary people, which is easy to understand, because under the existing power system, the power generation cost of power generation enterprises lacks competition constraints, and the feed-in tariff is not formed in competition, so it is meaningless to talk about low electricity prices or high power supply costs. Of course, the introduction of a competition mechanism in the electricity market does not mean that the price of electricity will necessarily decrease, but only that the competition mechanism will increase the credibility of cost information and price formation, which is the essence of the problem. Behind the pricing problem is actually the problem of the power system, but also the problem of the electricity market mechanism. But the current situation is that although power generation production has been marketized, sales have not yet been marketized, the wholesale electricity market has not yet been established, the on-grid tariff is still controlled by the state, electricity sales are still under the control of the state, and the power grid company is unified purchase and sales. Since the State Council's No. 5 Document in 2002 clarified the direction of electricity marketization reform, the electricity reform can be said to have made slow progress, and the fundamental reason is the lack of motivation for reform. Hicks said that the biggest benefit of monopoly is the possibility of enjoying a leisurely life, that is, it is too easy to make money from a monopoly position. Promoting the reform of the electricity market means that there will be huge resistance to touching the interests of many people. When it is difficult to promote the reform of electricity marketization, it will rely on the existing electricity price formation mechanism and solve many contradictions through price increases. However, rising prices will undoubtedly create great tension, which the government is undoubtedly very aware of. One of the interesting things about this electricity price reform is that the relevant departments are very smart, they know that simply according to the original pricing method, the opinions of the people will definitely be very large, which will affect the image of the government, so while raising prices, the theme of saving resources is highlighted, because rich people generally consume more electricity, so in the pricing scheme, let these people pay higher electricity prices. In this way, the price increase occupies the moral high ground and looks beautiful. In fact, one of the main features of this price increase is that the price adjustment plan implies the idea of income redistribution, which gives people the feeling that the price increase itself is in pursuit of fairness and justice, and the rational rhetoric of value has eliminated the antagonistic emotions of many people. However, it is clear that tiered pricing itself does not solve the problem of electricity price formation mechanism, in essence, tiered pricing is nothing more than a wonderful reason for price increases. Even the tiered pricing reform reflects some of the signs of current reform, that is, pan-value theory has replaced instrumental rationality. Second, the income distribution narrative gives ladder pricing the function of regulating income distribution, which shows that the government recognizes the people's dissatisfaction with the current income distribution situation, and also reflects that there are many problems in the traditional income distribution adjustment method of fiscal taxation. But even if tiered pricing is used as a tool to regulate income redistribution, or electricity consumption as a means of redistribution in kind, it is still necessary to consider whether it is the most effective way. The most basic feature of tiered pricing is that the applicable marginal price increases cumulatively as electricity consumption increases. According to the most basic economic common sense, this pricing method violates the law of electricity costs, because the long-term incremental costs of electricity production, including variable costs, exclusive fixed costs and capacity costs, do not change with the increase of electricity consumption. What better reflects this cost structure is two-step pricing, or real-time pricing, rather than tiered pricing. Tiered pricing without a cost basis is undoubtedly contrary to the principle of efficient economy and will produce unnecessary welfare losses. When considering whether to use distorted relative prices to achieve income distribution goals, there is a very famous principle in economics called the Arcson-Stiglitz theorem, which is a basic principle that government pricing must first consider in any field. Its main meaning is that under general conditions, income distribution does not need to distort prices, but only with the help of tax means, and adjusting income distribution by price means is doomed to be inefficient. Price is price, and its purpose is simple, it is to act as a signal of resource allocation, and it cannot do anything else, including regulating income distribution. If the distribution of income is adjusted by price means, it will inevitably pay the price of resource allocation efficiency. Of course, the real world is complex and does not necessarily meet the conditions of the Arcson-Stiglitz theorem, so there is room to regulate income distribution by means of prices. In essence, rationality for improving income distribution by means of price depends on how the loss of welfare caused by price distortions compares with the efficiency of the tax system. An important concept is used here, called the marginal cost of public funds, which simply means the social cost of each dollar of tax collected. Generally speaking, the tax system of developed countries is more efficient, so it is more reasonable to use fiscal taxation methods; Developing countries, on the other hand, have less efficient fiscal and tax systems, higher costs of public funds, and more room for the use of price instruments. Even so, welfare losses from price distortions need to be specifically considered, preferably through moderations designed to target specific groups. In real life, one danger of using price to improve income distribution is that income distribution goals are often used as an excuse to protect monopolies, because distorted prices, including ladder pricing, are incompatible with the competitive mechanism, and only under the monopoly system, relying on coercive force, this mechanism can be implemented, in this sense, ladder pricing includes monopoly thinking. Now, many industries have proposed universal service goals, that is, to provide services to everyone, regardless of the cost of services or ability to pay, but the problem is that the provision of these services may be at a loss, such as highlands or remote areas, users with relatively low income levels, in the absence of direct government subsidies, the provision of services needs cross-subsidy, and this cross-subsidy mechanism eventually evolves into a monopoly excuse. It must be emphasized that tiered pricing does not meet the incentive compatibility constraints of consumers and therefore does not give consumers choice. That is to say, if consumers are given different marginal price choices, they will definitely choose lower prices, so ladder pricing can only be implemented by coercive force. In contrast, in the field of telecommunications, consumers already have the right to choose telecommunications tariffs, and under the monopoly system, it is impossible to have such a choice. In addition to the issue of efficiency, improving income distribution by distorting prices also involves the issue of procedural justice, which is related to the mashup of "price" and "tax". According to the National Development and Reform Commission, part of the expected overcharge after the price increase will subsidize the increase in the cost of power plants, and the other part will subsidize the cost of desulfurization, which is part of the internalized external cost. Of course, there are external costs that have not yet been internalized. From this point of view, ladder pricing has a threefold mission: first, to recover the cost of electricity; The second is to internalize the external cost of electricity use, that is, the "Pigou tax", which is equivalent to paying environmental costs in addition to direct costs after consumers consume electricity; The third is to regulate income distribution. In ladder pricing, there is both the meaning of price and the concept of tax, but the problem is that "price" and "tax" are mixed together, for consumers, only know that like personal income tax, ladder pricing is a progressive tax, but do not know which part is the price paid, which part is paid "Pigou tax", and which part belongs to the distribution of income in kind. Of course, this phenomenon does not only exist in electricity pricing, and the mixing of price and tax is actually a norm, and ordinary people do not know their tax payment behavior. It is not obvious what the social cost of residential electricity consumption is to the consumption of resources, and the amount of electricity used. Obviously, it cannot simply be said that the more electricity is used, the higher the marginal cost. Although the progressive Pigou tax has the function of adjusting the distribution of income, it is not reasonable from a pricing point of view, not to mention that the relevant authorities have not even measured the cost of electricity production and environmental costs. Even if the power industry, as a special industry, has a logical basis for increasing the Pigou tax in the use link, it is necessary to separate the price and tax, make the price and tax transparent, so that it is also conducive to the establishment of civil society, let the people know their tax obligations, and at the same time make the government responsible for the money collected, which is the requirement of procedural justice in pricing and taxation. However, the government's current approach is to only explain what the money will be used for after the price increase, that is, to set the current collection with the future use, without providing transparency of prices and taxes, so it gives the impression that it is to raise prices. Third, the dilemma of the resource conservation proposition is to save energy and protect the environment by imposing a Pigou tax to make users bear the entire social cost of electricity. However, saving energy is not a simple proposition, even if raising the price of electricity can reduce electricity consumption, it does not mean that energy consumption is reduced, and the proposition of saving energy needs to be considered on a larger scale. Increasing electricity prices can reduce electricity demand and thus save energy, with the assumption that consumers will lower their overall energy demand because they pay more. This assumption is not necessarily true, because consumers do not necessarily reduce their overall demand for energy because of the increase in electricity prices, and are likely to switch to other alternative energy sources. The complexity of the resource conservation proposition is that the demand for electricity is not the final demand, but a demand caused by other consumption, that is, people need not electricity itself, but use electricity to do other things. The problem is that there are many types of energy and they are interchangeable, in economic terms, that is, raising electricity prices not only has a revenue effect, which therefore suppresses electricity demand, but also has a substitution effect, and the method and degree of substitution depends on short- and long-term considerations. For example, cooking can use electricity or natural gas, and when the price of electricity increases, people will use more natural gas to meet the needs of cooking. In addition, changing electricity prices may change people's lifestyles, but they will not necessarily change people's energy needs. For example, when the price of electricity is very low, many people are used to using computers to read online, but if the price of electricity rises, it is likely to be printed out for reading. Although less electricity is used, but more paper is used, which way can save energy and which way is more environmentally friendly? In the previous stage, many people discussed whether electric vehicles were energy-saving or more environmentally friendly. From the perspective of the way electric vehicles replace driving, electric vehicles will reduce gasoline consumption, so it does save energy, however, electric vehicles are charged and need to be recycled and processed batteries, and the potential impact of rechargeable batteries on the environment may be difficult to estimate, and many experts even believe that in the long run, it produces much more pollution than gasoline use. From the characteristics of electricity itself, electricity is a secondary energy, compared with primary energy, it is itself an efficient and clean energy, which is why the country vigorously develops electricity and why it spends so much money to build a transmission network. If the price of electricity rises and the price of other energy sources remains unchanged, people will choose alternative energy sources, or alternative lifestyles, so it is difficult to say whether the price increase will reduce energy demand. If the total demand for energy remains the same, it is obviously not worth the loss to replace electricity with less efficient and environmentally unfriendly energy. Fundamentally, the consumption of resources depends on the mode of growth, or more precisely, the speed of economic development. It is undeniable that the current global resource pricing is difficult to reflect the full cost, and some major environmental pollutants such as carbon dioxide have the attributes of global public goods, under such conditions, economic growth is actually a "free rider" behavior, changing the mode of growth is difficult to commit political will, in the absence of a global constraint mechanism, it is difficult for any government to restrain the impulse to grow. From this point of view, it is unrealistic to adjust energy demand simply by raising electricity prices, rather than drastically changing the growth pattern and slowing down the pace of development. IV The Challenge of Ladder Pricing If the introduction of ladder pricing is a political choice, then whether it is to return electricity prices to rationality, or to adjust income distribution, or to promote energy conservation, to achieve these good intentions, it is necessary to formulate and implement reasonable ladder prices, but because of some attributes of ladder pricing itself, the adoption of this pricing method faces great challenges. In this regard, both the academic community and the price authority must have sufficient understanding, otherwise it will be difficult to achieve its effect. According to the basic principles of microeconomics, there are two issues that deserve special attention to cumulative tiered pricing: First, the mutual influence of different electricity prices. In the case of multi-level electricity prices, an important property of tiered electricity prices is that low-grade electricity prices have a pure income effect on high-end electricity price consumers, but there is no substitution effect, that is, raising low-grade electricity prices suitable for low-income consumers will more effectively suppress electricity consumption, which is a paradox of tiered pricing. This paradox means that there is a helpless trade-off between the price level of electricity and changing consumer behavior: the low-end electricity price of option 2 is higher than the low-end electricity price of option 1, but due to the income effect generated by the ultra-marginal price, although the high-end electricity price level of option 1 and option 2 is the same, under option 2, not only will low-end electricity consumers reduce consumption, but also high-end electricity users will reduce electricity consumption relative to option 1. Second, there is a concentration of electricity consumption at the inflection point of ladder pricing, that is, many consumers with different preferences will choose the same level of electricity consumption at the inflection point with each other. This is tantamount to saying that tiered pricing may reduce rather than increase demand effects, which is clearly contrary to the principle of effective electricity pricing, which is another paradox of tiered pricing. This important feature of incremental ladder pricing will affect the choice of different electricity price levels and the determination of inflection points of different gears. At present, it is difficult to know whether the relevant authorities are concerned about the technical problems caused by this shift in pricing. However, it should be emphasized that these considerations are not only purely technical, and in the era of tiered pricing, these seemingly difficult technical issues mean that price authorities must face the technical challenges brought by non-linear pricing, especially reflected in the need for micro-information. In the era of linear pricing, the formulation of optimal pricing does not need to consider the consumer's preference information, but only needs to know the aggregate demand information, because as long as there is elastic information and cost information on the total demand for electricity, the optimal electricity price can be determined in accordance with the Ramsay pricing principle. However, as a non-linear pricing, tiered pricing has revolutionized information demand, and the adoption of tiered pricing means that it is not enough to set the optimal price to understand the total demand, but also to understand the individual demand information. This is undoubtedly a methodological revolution for price authorities accustomed to linear pricing. Of course, from the actual point of view, this rational appeal may be too harsh, and the government pricing may not pay too much attention to this instrumental rational requirement, or it can only meet part of the rational demand. For example, for various reasons, the inflection point of tiered pricing may be determined by politics, and the policy tools of price authorities become only to optimize electricity prices in different levels, in which case the linear pricing thinking of the past may still apply to some extent. However, according to the current information, it is impossible to judge the rationality of the level of electricity prices in different levels, and the National Development and Reform Commission proposes that the determination of inflection points should be decided by each locality, but it is impossible to know the criteria for determining these inflection points. It must be noted that the absence of effective pricing may not affect the political correctness of tiered pricing or its implementation, but governments and the public must recognize that the resulting opportunity costs are enormous, and although this opportunity cost is implicit, it is not fundamentally different from any way that directly reduces consumer welfare, such as reducing consumer income, or reducing consumer satisfaction. Another challenge posed by tiered pricing will be reflected in the evaluation of its effectiveness after implementation. It can be expected that after the implementation of tiered pricing, whether government departments or academia, in order to evaluate the implementation effect of tiered pricing, or for the purpose of improving tiered pricing, it is necessary to conduct empirical research on the effect of tiered pricing, such as estimating the relevant elasticity. However, under tiered pricing, these empirical studies face great challenges, including the need to learn more about micro-information at the household level, and a series of technical difficulties, such as how to account for the impact of marginal and average prices. Failure to properly consider these issues will mislead future pricing policies. V. The previous analysis of the future of electricity price reform shows that tiered pricing is at best a means of regulating income distribution, but it is far from solving the core problem of electricity prices, that is, promoting the effective allocation of resources in the power industry. So what is effective pricing in the power industry? The answer lies in real-time pricing. The most basic techno-economic feature of the power industry is that the potential demand and supply of the power system may be unbalanced, but the power system must be balanced at all times. Given at any point in time, if the power demand is insufficient and the power supply is excessive, the power supply system needs to reduce the power generation and transmission, otherwise the power system will have problems, such as the fuse will be blown and the electrical appliances will be destroyed; If there is excess demand and insufficient existing capacity, the power system will also go wrong, such as light bulbs going dark. Since there is uncertainty in electricity demand, and the increase in generation and transmission capacity is discontinuous and comes at a cost, the eternal theme of the power system is how to manage demand in the short term and with limited capacity; In the long term, promote a reasonable increase in capacity. This characteristic of power products determines that the pricing of the power industry is different from the pricing of general products, and the optimal pricing of electricity must be related to a specific time and space. Effective pricing in the power generation industry needs to solve problems that are very similar to those of other industries with capacity constraints, such as transportation. For the transportation industry, supply and demand are often mismatched. For example, during the morning or evening rush hour, the road network is very crowded and cannot meet the demand for vehicles, but in addition to most of the time, there are not so many cars, and the road network is largely underutilized. More and more road congestion problem, not only in the construction of the road can not keep up with the increase in vehicles, in a certain period of time, the supply is indeed limited, the road can not increase at once, because building a road not only requires funds, but also a certain amount of construction time, more importantly, maintaining a certain blockage is in line with the principle of efficiency. The same is true of the power system, where supply is difficult to meet all demand during peak demand, so demand management and even power cuts are required, but most of the time, the supply is excessive. The technical and economic characteristics of the power industry determine that the pricing method for effective allocation of power resources is real-time pricing. In real-time pricing, one of the simplest pricing methods is peak-to-valley pricing, which is when electricity prices are higher during peak hours; In the trough stage, the price of electricity is lower, so that consumers have an incentive to choose to avoid the peak and valley period of electricity. The implementation of real-time pricing is the main trend of international electricity price reform. Technically, implementing peak-to-valley electricity prices, or even more complex real-time pricing, is not a problem, which is to install a smart meter to distinguish electricity consumption at different times. In fact, China has tried to do this for a long time, but it has not been rolled out on a large scale, and there are many reasons for this, the most important of which is related to our system. Under the existing monopoly system, companies have no incentive to do so, and they certainly prefer to make money in the simplest way. For future electricity price reform, there is still huge room for reform under the framework of introducing tiered pricing. The option that can be considered is to embed real-time pricing (peak-valley pricing) in tiered pricing, so that different goals can be achieved by different means, among which, peak-valley pricing mainly undertakes the mission of effective pricing, while tiered pricing more assumes the function of social regulation, which may be the direction that the next step of electricity price reform can work towards. But it all depends on the momentum for change that stakeholders have. Zhang Xinzhu, June 2015（AI翻译）