We extend the immigration surplus results of Borjas (1995). In a closed competitive constant-returns economy, we show that an influx of migrants (holding their skill mix fixed) must increase the total real income of natives, for any number of factor inputs, any pattern of substitutability or complementarity between them, and any number of intermediate or final goods - with larger gains if natives and migrants differ more in skill mix. If natives supply labour elastically across skill types, their welfare gains are diminished, even if they respond by moving to higher-paying jobs. We illustrate our results using a US calibration.

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Available online 19 October 2026

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The Economic Journal 2026

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DOI: https://doi.org/10.1093/ej/ueag133

https://academic.oup.com/ej/

This Journal article is published under the centre's Labour programme.