Treballs Finals del Grau d'Economia, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2015-2016 , Tutor: Joan Gil Trasfi(eng)Social insurance program is a universal model provided by the Pubic Sector with the aim of covering risks such as retirement, widowhood or disability over the population with the provision of either cash payments or services. One of the popular cash payments is the pension-retirement income. In Spain, this pension is based on a pay-as-you-go system (PAYG). But the Spanish pension system has to face some structural problems, like the aging of population and the increase in the dependency ratio. After some reforms were initiated in order to improve the financial sustainability of the pension system, some other strategies have been proposed to enhance these reforms, such as changing the way pensions are based, i.e. a shifting from PAYG to other pension plans like definedbenefit plans (DB) or defined-contribution plans (DC). A cross-country comparison between Spain and Denmark will give us an insight of the differences between these two countries and try to ask whether the pension system of a well-performed country can also be a good solution for Spain.