摘要：制度作为一种产品，也存在边际收益递减问题。关键是人性具有机会主义倾向，这会不断蚕食制度的约束效应，从而使制度的边际收益递减。也就是说，一项新制度刚执行的时候，可能还具有较大约束效应，但越往后，制度的约束效应越差。比如，中国的反腐败制度，我国现代著名历史学家钱穆

制度也存在边际收益递减问题

宋 圭 武

历史发展的实践证明，制度需要不断进行变革。变是永恒的，不变是短暂的。坚持不变，不符合历史发展的辩证法，也不符合制度的辩证法。

制度作为一种产品，也存在边际收益递减问题。关键是人性具有机会主义倾向，这会不断蚕食制度的约束效应，从而使制度的边际收益递减。也就是说，一项新制度刚执行的时候，可能还具有较大约束效应，但越往后，制度的约束效应越差。比如，中国的反腐败制度，我国现代著名历史学家钱穆（1895—1990）提出存在所谓钱穆陷阱，即是制度边际效应递减的典型案例。

如何克服制度的边际效应递减问题，需要不断创新制度。如何创新制度，应立足制度边际收益递减的时间周期来设计。从时间上来看，不同层面制度可能具有不同的时间周期。对于关系国家层面的大制度，可能周期更长一些，对于涉及地方及单位的小制度，可能周期更短一些。比如，一个单位员工的业绩考核制度，可能5年左右就需要重新修订一次。对于一个县的有关制度，可能10年左右就需要大修订一次。而涉及一个国家层面的大制度，可能30年左右就需要大改革一次。人们常说，三十年河东，三十年河西，大体也是说三十年往往有社会大变革或需要社会大变革。

对于国家层面，市场经济和计划经济就是最大层面的制度设计。立足时间周期考虑，国家应以三十年左右为周期，不断创新体制。即，三十年以市场经济为主，然后三十年，以计划经济为主，再然后三十年，以市场经济为主，以此类推。这样通过制度的不断调整，可以有效克服制度的边际收益递减问题，使制度发挥整体最优功能。

上个世纪八九十年代以来，中国不断推进市场经济改革。若从1992年算起（统购统销政策1992年正式退出历史舞台，同年，中国共产党第十四次全国代表大会确定我国经济体制改革的目标是建立社会主义市场经济体制），中国市场经济已经满三十年，为此，笔者认为，从2022年左右开始，国家可考虑更多立足计划经济方向推进中国经济体制改革。

如何立足计划经济方向推进中国经济体制改革。第一，应进一步加大对国民经济计划调控的力度。第二，对一些国计民生的关键行业，要多一些公有制成分。比如，医疗、教育等，要多公办，尤其婴幼儿教育，更要多一些公办。再比如，农业，也要充分发挥公有制和计划调控的优势，不能过于市场化。具体比如，农产品价格，就不能波动太大，否则，对整个国民经济健康发展都不好。如何防止农产品价格波动大问题，对于一部分重要农产品，国家应实行价格管控政策，或实行国家统一定价。

这里需要注意的是，对于制度变革，不能理解成是对过去制度的简单重复，而应理解成是否定之否定，是螺旋式上升过程。比如，我们现在强调向计划经济靠拢，这里就不能理解成是对过去计划经济体制的简单重复，而应是对过去计划经济优点保留基础上的再创新和新综合。比如，过去我们对农产品统购统销，但存在问题是管得太死，导致弊端较多，现在我们也可以对农产品统购统销，但不能太死，应具有一定灵活性，比如，可以实行半统购统销政策。目前，对部分农产品实行半统购统销政策，对保护农民利益免受市场伤害，有重要意义。

总之，变是历史永恒的主题，制度的变革也是制度永恒的主题。面对制度的边际收益递减问题，我们应立足时间周期，不断推进制度变革，这既是历史的辩证法，也是制度的辩证法。（作者：兰州城市学院特聘教授，原中共甘肃省委党校（甘肃行政学院）二级教授）

Institutions also suffer from the problem of diminishing marginal returns.

Song Guiwu

The practice of historical development has proved that systems need constant reform. Change is eternal, while constancy is transient. To insist on constancy does not conform to the dialectics of historical development or the dialectics of systems.

As a product, a system also faces the problem of diminishing marginal returns. The key lies in the opportunistic nature of human beings, which constantly erodes the constraining effect of the system, leading to the diminishing marginal returns of the system. That is to say, when a new system is first implemented, it may still have a significant constraining effect, but as time goes by, the constraining effect of the system becomes weaker. For instance, China's anti-corruption system is a typical case of the diminishing marginal effect of a system, as pointed out by the renowned modern Chinese historian Qian Mu (1895-1990), who proposed the so-called Qian Mu Trap.

To overcome the problem of diminishing marginal returns of systems, continuous innovation of systems is necessary. How to innovate systems should be designed based on the time cycle of diminishing marginal returns. From a temporal perspective, different levels of systems may have different time cycles. For major systems at the national level, the cycle may be longer, while for smaller systems at the local or organizational level, the cycle may be shorter. For example, the performance appraisal system for employees in an organization may need to be revised every five years or so. For a county's relevant systems, a major revision may be needed every ten years or so. And for major systems at the national level, a major reform may be needed every thirty years or so. As the saying goes, "Thirty years on the east bank of the river, thirty years on the west bank," which roughly means that there is often a major social transformation or the need for a major social transformation every thirty years.

For the national level, market economy and planned economy are the largest-scale system designs. Considering the time cycle, the country should take about thirty years as a cycle to continuously innovate the system. That is, for thirty years, the market economy should be the main focus, then for another thirty years, the planned economy should be the main focus, and then for another thirty years, the market economy should be the main focus, and so on. Through continuous adjustments of the system, the problem of diminishing marginal returns of the system can be effectively overcome, and the overall optimal function of the system can be achieved.

Since the 1980s and 1990s, China has continuously advanced market economy reforms. If we start from 1992 (the year when the policy of unified purchase and sale officially exited the historical stage and the 14th National Congress of the Communist Party of China determined that the goal of China's economic system reform was to establish a socialist market economy system), China's market economy has been in place for thirty years. Therefore, the author believes that starting from around 2022, the country can consider more focusing on the direction of planned economy to promote China's economic system reform.

How to promote China's economic system reform in the direction of planned economy? First, the intensity of national economic planning and regulation should be further increased. Second, for some key industries related to the national economy and people's livelihood, there should be more public ownership components. For instance, in healthcare and education, there should be more public institutions, especially in infant and toddler education, where there should be more public institutions. Another example is agriculture, where the advantages of public ownership and planned regulation should be fully utilized, and it should not be overly marketized. Specifically, the prices of agricultural products should not fluctuate too much, otherwise, it will be detrimental to the healthy development of the entire national economy. To prevent large fluctuations in agricultural product prices, for some important agricultural products, the state should implement price control policies or set unified prices.

It should be noted that the reform of systems should not be understood as a simple repetition of past systems, but rather as a process of negation of negation and a spiral ascent. For instance, when we now emphasize moving closer to a planned economy, this should not be understood as a simple repetition of the past planned economy system, but rather as an innovation and new synthesis based on the retention of the advantages of the past planned economy. For instance, in the past, we implemented a policy of unified purchase and sale for agricultural products. However, the problem was that it was too rigid, leading to many drawbacks. Now, we can also adopt a unified purchase and sale policy for agricultural products, but it should not be too rigid and should have a certain degree of flexibility. For example, a semi-unified purchase and sale policy can be implemented. Currently, implementing a semi-unified purchase and sale policy for some agricultural products is of great significance in protecting farmers' interests from market harm.

In conclusion, change is the eternal theme of history, and the reform of systems is also an eternal theme of systems. In the face of the diminishing marginal returns of systems, we should base ourselves on the time cycle and continuously promote system reform. This is both the dialectics of history and the dialectics of systems. (Author: Distinguished Professor of Lanzhou City University, former Professor of the Communist Party School of Gansu Province (Gansu Administration College))

来源：宋圭武