Table 1. z_a,g and t parameter values for which the highest R² values were obtained when correlating the training subsets of the log(FN_mig_cor^{i = r}_{a,g,o,d,p = 1}) and the log(acs_a,s,o,d).

We performed four rounds of cross-validation by randomly selecting in each round 51 countries of birth as the training subset and the remaining 25 countries of birth as the testing subset.

	g	a	Training subsets, 51 countries of birth in the US				Median	Training with Eurostat [8]
			1a	2a	3a	4a
za,g	female	15–24	0.8	1	0.9	0.8	0.85	0.85
		25–39	1	0.8	0.7	0.7	0.75	0.5
		40–54	0.1	0.3	0.4	0.3	0.3	0.3
		55–64	0	0.3	0.3	0.2	0.25	0.3
	male	15–24	0.7	1	0.9	0.9	0.9	0.95
		25–39	1	1	0.8	1	1	0.8
		40–54	0.4	0.6	0.6	0.6	0.6	0.8
		55–64	0.5	0.9	0.6	0.6	0.6	0.85
t			0.6	0.2	0.2	0.3	0.25	0.25
Training Max R2			0.92	0.90	0.90	0.91	0.91	0.83
			Testing subsets, 25 countries of origin in the US
			1b	2b	3b	4b
Testing R2			0.87	0.90	0.90	0.86