Resumen
This paper analyzes the future impact of the implementation of the sustainability factor, introduced in the last reform of the Spanish public pension system. This factor aims to regulate the initial pension according to the evolution of life expectancy. Additionally, it examines what could have happened in case of an earlier implementation of the factor. The results show that the factor produces a progressive pension reduction if life expectancy continues to increase, and pension spending is adjusted to demographic evo- lution. Specifically, the initial pension could be reduced up to 23% in 2051 if the demographic trend does not change.