This thesis explores and reviews extensively previous studies on the economic impact of mass immigration on Sweden with a special interest in the native population, addressing the widespread belief that the inflow of immigrants means a strain on the country's resources and negatively affects the natives. The research distinguishes between voluntary and involuntary migration and examines their respective contributions and challenges to economic growth, educational opportunities, and social mobility. Using literature and data from Statistiska Centralbyrån (Statistics Sweden)(SCB), Migrationsverket (Swedish migration services), and various empirical and theoretical studies, the research conducts an extensive literature review and analyzes whether immigration acts as an economic gain or drain for Sweden. Key aspects analyzed in the literature include but are not limited to employment dynamics, country of origin, age distribution, and education levels of immigrants. The findings uncover a complex interplay between the economic benefits and challenges posed by immigration, highlighting mixed outcomes in terms of labor market integration, wage impacts and public welfare contributions. This comprehensive analysis aims to provide a nuanced understanding of how mass immigration impacts Sweden's economy and the welfare of its native population. Keywords: Immigration, Public sector finance, native impact, fiscal effect