Abstract: In 2022, China implemented the policy of national pooling of pension insurance for urban employees, replacing the central adjustment scheme with the pooling adjustment scheme, and making inter-provincial adjustment to the pension insurance fund. Existing literature analyzed the financial burden and sustainability of the pooling adjustment scheme, but haven't yet focus on the measurement of its adjustment effect. Based on this, the article constructs an actuarial model of pension insurance, compares the central adjustment scheme, analyzes the trend of the inter-provincial disparity of the fund under the pooling adjustment scheme, and further explores the optimization path: first, on the inter-provincial disparity of the current fund balance, the pooling adjustment scheme will be lower than the central adjustment scheme only in the years of 2023-2028, and will be the lowest in the year of 2025, which is a decrease of 95.93% compared with the central adjustment scheme; on the inter-provincial disparity of the fund's payable level, the pooling adjustment scheme is lower than the central adjustment scheme in the measurement period. Secondly, starting from 2026, the national current balance will be insufficient to form the pooling adjustment fund demand of the pooling adjustment scheme, resulting in a continuous decline in the adjustment effect. Third, the cumulative balance re-adjustment can optimize the adjustment continuity, in which the 48.5% part of the cumulative balance re-adjustment mode can maintain the adjustment effect and balance the fund's cumulative balance expenditure and fiscal expenditure. It is recommended to plan the cumulative balance re-adjustment option and improve the incentive mechanism for premium collection.

Key words: national pooling, pension insurance, inter-provincial disparity, fund adjustment