While various studies have already shown that people prefer high-over low-skilled migrants, we know surprisingly little why this is so. This article tries to close this gap by investigating three explanatory models. (i) According to the labour market competition model, citizens oppose immigrants with the same skill levels who are perceived as competitors on the job market. (ii) According to the welfare state model, low-skilled immigrants' use of public services is disproportionally higher than their contribution to tax revenues contrary to high-skilled immigrants. (iii) According to the deservingness model, high-skilled immigrants are preferred, as low-skilled immigrants are considered as lazy people who would be as well off as natives if they only tried harder. As one of the first studies outside the United States, these arguments are tested by means of an experimental online survey in Switzerland. Respondents were randomly assigned to evaluate low-and high-skilled immigrants. We find that different groups prefer high-over low-skilled immigrants for different reasons: While the labour market competition model does not play a role, the welfare state model only holds for natives who are well off in regions with low taxes. Finally, attitudes on deservingness explain preference of high-skilled immigrants only if the respondents have a high income.