社保缴费基数的跨期收入配置功能、收入分配效应与社会福利效果研究

本项目旨在考察社保缴费基数及其上、下限规则对城镇企业职工收入分配、福利，以及企业行为的影响，并通过模拟仿真探索最优社保缴费基数的制定与调整。一方面，项目测算了社保缴费基数及其上、下限规则对劳动者的跨期收入配置功能，并结合地区收入分布情况分析由此引致的收入分配效应。进一步结合消费理论，估计了社保缴费基数对劳动者生命周期消费和福利的影响。另一方面，项目分析了社保缴费基数对企业社保缴费规避和劳动力需求的影响，并结合劳动者的地区迁移选择，从劳动供给和需求的均衡视角推算社保缴费基数规则的社会整体福利效果，进而通过模拟仿真，寻找不同政策目标下最优社保缴费基数规则。本项目的研究将为社保缴费基数这一重要社会保障政策的调整和改进提供研究支持，同时在研究方法上也将对后继研究有所裨益。

This Project studies the labor welfare implication of social security payment base figure in China, as well as its impact on firms' behavior. Optimal social security payment base figure under different policy regions are also considered by theory-based numerical simulation. Specifically, we estimate the inter-temporal income allocation effect and the distributional implication of social security payment base figure according to its policy rules. We incorporate social security payment base figure into a standard life cycle consumption/saving model and evaluate its impact on household consumption and welfare of different income group. We further assess the impact of social security payment base figure on firms' social security payment evasion, labor demand and wage offer. Coupled with labor mobility choice, we estimate the aggregate welfare implication of social security payment base figure and its social optimal setting. This study is aiming at providing research support for the possible improvement of social security policies in China, and the analytical framework used in this project will benefit subsequent studies as well.