 A paper by Spanish economists found that upon legalizing the undocumented immigrant population in Spain, the fiscal revenues increased by around €4,189 per newly legalized immigrant.The paper found that the wages of the newly legalized immigrants increased after legalization, some low-skilled natives had worse labor market outcomes and high-skilled natives had improved labor market outcomes.According to economist George Borjas, immigrants may have caused the decline of real wages of US workers without a high school degree by 9% between 1980 and 2000 due to increased competition.