上世纪90 年代以来，新制度主义经济学家们在“制度很重要”这一观点上基本达成了共识，但通常我们忽略了另一个重要的议题，那就是制度变迁的方式同样重要。即便是同样从“坏”制度向“好”制度转型的过程中，不同的制度变迁方式可能导致不同的经济绩效。以往的研究精力主要集中在识别“好”的或者“坏”的制度上面，但对于如果使用适当的方式推动制度改革以提高经济绩效的相关研究没有得到足够的关注。研究制度变革及其方式是研究经济动态（尤其是对转型经济体来说）的重要任务。以中国户籍制度的演变为典型的制度变迁案例，本文旨在从内生制度变迁的角度研究户籍制度演变与中国经济转型之间的相互作用关系。
    首先，本文建立了户籍制度变迁的理论研究框架。通过对前人关于制度变迁理论成果的梳理，本文认为，与外生制度变迁理论相比，内生制度变迁理论在分析制度变迁方面具有一定优势。借鉴前人研究成果，本研究构建了一个内生性制度变迁的理论框架，以分析户籍制度形成和改革的动力。基于对学术界关于制度效率评估相关研究的梳理，认为，适应性效率所强调的动态性理念更符合经济现实，为评估制度效率提供了一个新的路径，因为制度所处的经济环境是具有不确定性，非各态历经和动态性的。因此本文建立适应性效率理论框架来评估户籍制度的制度效率。基于相似的理论基础，本研究进一步建立了内生性制度变迁理论和适应性效率理论之间的理论桥梁。
    其次，本文对当代中国户籍制度演变进行了全面的历史回顾，梳理了在计划经济体制下户籍制度形成过程，以及经济转型过程中户籍制度改革历程。基于所建立的理论分析框架，本研究表明，虽然中国户籍制度的演变是外生与内生力量相结合的结果，但改革开放前后，户籍制度的制度化和改革的主要驱动力有所不同。在改革前时期，户籍制度的制度化主要是自上而下的外生性制度变迁过程，政府，尤其是中央政府，强制实施力量起到主导作用，而个体和地方政府的创造性被很大程度上忽略了；户籍制度的改革是自下而上驱动的内生性制度变迁过程，通过政府与市场、中央与地方力量之间的再平衡，市场和地方自发力量得到回归。研究结论表明，户籍制度不仅深刻影响着中国的经济发展，反过来，中国经济的发展与转型也深刻塑造着户籍制度的演变轨迹。
    再次，本研究运用适应性效率理论框架，并建立耦合模型来评估户籍制度演化的制度效率。从适应性效率的五个方面对改革前后户籍制度进行研究，发现，户籍制度的改革明晰了劳动力的产权，促进了分散决策机制的形成，强化了竞争的作用，降低了劳动力流动的交易成本，以及保持了一定的制度灵活性以提高制度创新，这都对户籍制度适应性效率提高起到重要作用。利用耦合模型实证结果显示，改革后的户籍制度适应效率远高于改革前，但2008 年以来呈现出适应性下降和适应性效率边际增长率递减趋势。这表明中国的户籍制度改革和现有的户籍制度仍具有一定适应性效率，但随着制度环境的改变，如劳动力成本上升，社会不公加大，户口与福利的绑定关系所导致的交易成本过高等一系列问题导致了其适应性的下降和制度效率的递减。
     最后，尽管当前的户籍制度对经济环境的适应能力正在下降，但它仍然具有一定程度的适应性效率。因此，如何解释当前户籍制度的适应性效率是理解目前户籍制度粘性的关键。本研究借鉴公共支出相关理论建立了经济学分析框架，通过使用内生增长模型检验户籍制度对城市经济增长的影响，以在地方层面解释当前户籍制度的适应性效率。结果发现，户籍制度改革对城市经济增长影响显著。第一，在允许流动人口在城市工作，但仅能享有非排他性公共服务的条件下，城市能够从放松劳动力流动性管制方面获得经济效益；第二，户籍制度改革对不同规模，不同行政级别城市的经济增长影响不同。相比与小城市或行政级别低的城市，户籍管制对大城市或者行政级别高的城市经济增长具有更大的促进作用。反过来，在户籍与福利绑定的情况下，大城市或者行政级别高的城市也更容易在激进的户籍制度改革中受损。这也就解释了为什么大城市对户籍制度改革倾向于更加谨慎的问题；第三，户籍制度改革过程中，为抵消向流动人口提供排他性公共服务的成本，并从中获得经济效益，大型或高行政级别的城市可以利用其较高价值的户口吸引高技能劳动力，但是小型或低行政级别的城市则没有这个优势。因此，户籍制度的存在不仅为城市经济增长降低了成本，而且大型或者行政等级高的城市可以利用户籍制度管制为当地经济发展创造条件。
     本研究具有重要的政策含义。本文认为，为提高制度效率，进一步的户籍制度改革过程中，决策者应尊重制度内生变迁的力量，遵循制度的适应性变化逻辑，“顺水推舟”，而不是“逆水行舟”。当前户籍制度改革的核心问题仍是如何处理户籍与社会福利（包括农村的土地和城市的福利）之间的联系。本文认为，改革的关键并不在于简单地打破户籍和福利的绑定关系，而在于如何降低以户籍为基础的农村土地交易和城市福利可获得性的交易成本。这需要户籍制度与土地制度和财税制度的联动改革，其中包括促进土地交易的市场化以及提高私有部门参与公共服务供给能力等等。除户籍制度外，本研究中建立的内生性制度变迁的理论框架将有助于增进我们对经济动态背景下的制度变迁的理解，并使决策者对决策过程有更好的认知以提高经济绩效。

    Since the 1990s, New Institutionalists have united around the idea that “institutions matter.” Nevertheless, they commonly ignore an important issue – the ways to change institutions also matter. Much attention has been devoted to identifying “good” or “bad” institutions, but there has been comparatively less written about the proper way to transform “bad” institutions into “good” ones in a way that enhances economic performance. Understanding institutional change is an essential task in studying economic dynamics, especially for a transition economy. Regarding China’s hukou system evolution as a typical case of institutional change, this research seeks to analyze the interaction between China’s hukou system evolution and Chinese economic transformation from an endogenous perspective.
    First, this research builds up theoretical frameworks of the hukou system evolution. It holds that endogenous institutional change theory has certain advantages in analyzing institutional changes, compared with exogenous institutional change theory. Based on the previous research, this study constructs a theoretical framework of endogenous institutional change to analyze the driving forces of formation and reform of the hukou system. Also, a theoretical framework of adaptive efficiency is established to evaluate the hukou system’s institutional efficiency. The idea of dynamics emphasized by the concept of adaptive efficiency is more in line with economic reality because the economic environment in which institutions are located is uncertain, non-ergodic and dynamic. Furthermore, based on the similar theoretical basis, the study builds up a bridge between the theory of endogenous institutional change and adaptive efficiency.
    Second, this study makes a comprehensive historical review of the evolution of contemporary China’s hukou system and sorts out the process of the institutionalization of the system under the planning economy and the process of reform under economic transformation. Based on the established theoretical framework, the analysis suggests that although the system evolution results from the combination of exogenous and endogenous forces, the main driving forces of the system’s institutionalization in the pre-reform era and reform in the reform era are different. In the pre-reform times, the institutionalization of the hukou system is mainly a top-down enforced exogenous institutional change process, in which the government, especially the central government, enforcement forces play a dominant role, and the roles of individual and local government were largely neglected. The reform of the system is a fundamentally bottom-up driven endogenous institutional change process, in which spontaneous market forces and the role of local government bounce back to the stage through rebalancing the powers between the state and market and between central and local government. This research concludes that the hukou system profoundly affect China’s economic development, and in turn, the development and transformation of China’s economy have also deeply shaped the evolution of the system.
    Third, this research applies theory of adaptive efficiency and establishes a coupling model to evaluate the institutional efficiency of hukou system evolution. The five elements of adaptive efficiency concerning the hukou system evolution are investigated to helps us understand how the institutionalization of the system constrained its adaptive efficiency and how the system reform generated adaptive efficiency. It finds the reform of the system clarified property rights of the labor force, promoted the formation of a decentralized decision-making mechanism, strengthened the role of competition, reduced the transaction costs of labor mobility, and maintained a certain degree of institutional flexibility that rewards successes and eliminates failures in the system. All these have played critical roles in improving the adaptive efficiency of the hukou system. Empirically, the results show that the adaptive efficiency of the system in the reform era is much higher than that in the pre-reform era, but has had a marginal decreasing trend since 2008. This suggests that China’s hukou system reforms and the current hukou system do have adaptive efficiency, but the system is also facing difficulties. With the change of the institutional environment, including social inequality, rising costs of labor, and weak domestic consumption, the problem of high
transaction costs caused by the binding relationship between hukou and welfare hindered the further improvement of its institutional efficiency.
    Fourth, despite the fact that the current hukou system is showing a decreasing adaptiveness to the economic environment, it still has a certain degree of adaptive efficiency though experiencing a marginal decreasing trend. Thus, how to explain the adaptive efficiency of the current hukou system may be the key to understand the current stickiness of the hukou system. This study establishes an economic analysis framework and an endogenous growth model to explain the adaptive efficiency of the current hukou system at local level. It illustrates and tests the impacts of the system on city economic growth. The results provide three main findings. First, the city’s
economic growth can benefit from labor mobility deregulation that allows migrants to work in cities with the condition of only providing them with non-exclusive public services. Second, the hukou system reform has different impacts on economic growth among cities with different sizes and administrative levels. The big or high-administrative level cities will benefit more economically than small or low-administrative level cities from the hukou regulation. However, they will also financially suffer more if they radically deregulate the hukou system without getting rid of exclusive public services attached to it. Third, to offset the costs of providing exclusive public services to the migrants and develop the local economy, the big or high-administrative level cities can use their high-valued hukou to attract the high-skilled migrants, but the small or low-administrative level cities do not have this advantage. Therefore, the existence of the hukou system not only reduces costs for city economic growth but large-scale or high-level cities can benefit from using the system and create conditions for local economic growth.
    This research has some important policy implications: to further reform the hukou system and promote the institutional efficiency of it, decision-makers should respect the endogenous forces and follow the logic of adaptive change of an institution, pushing the “boat” along with the “current” rather than against the “current.” This study argues that the core issue of the current hukou system reform is how to deal with the hukou-welfare binding relationship. Rather than simply breaking down the binding relationship, the fundamental way to reform the hukou system is to reduce the transaction costs of hukou-based rural land transaction and urban welfare availability.
This requires the joint reform of the hukou system, the land system, and the fiscal and taxation system, including the marketization of land transactions, establishing fiscal sharing mechanism between the central and local, and improving the ability of the private sector to participate in the provision of public services.
    Beyond the hukou system, the theoretical framework of institutional change established in this study will help to improve our understanding of institutional change against dynamic economic context and offer policymakers a better perception in decision-making processes in order to enhance economic performance.