Statistical Analysis of Data Based on the Endogenous Growth Model to Study the Adequacy of Fiscal Social Security Expenditure and the Improvement of Social Security System

The purpose of this paper is to study the intrinsic mechanism of the impact of fiscal decentralization on social security expenditure from both theoretical and empirical perspectives, and to explore how China's social security system, as an extremely important function of the government, can reasonably and effectively determine the appropriate level of fiscal social security expenditure in which the "engine" role is assumed. By selecting "small-calibre" social security expenditure items, which are more in line with the current situation of big data applications in China, as statistical indicators of fiscal expenditure decentralisation, an endogenous growth model of central and local public goods supply is constructed to constrain social production and government budgets to obtain a general competitive equilibrium, and the first-order partial derivatives of fiscal decentralisation on local government public goods expenditure are calculated based on structural parameters. The study shows that there is a significant positive linear relationship between fiscal decentralisation and the level of local government public expenditure. The study further analyses the endogenous instrumental variables in the empirical model-public finance expenditure structure and transfer payments-on the decentralisation of affairs and the underlying mechanism by which fiscal decentralisation ultimately affects the impact of fiscal social security expenditure.