Table 7. Average target domain accuracy of all algorithms on the ACS Mobility and US Accident datasets. In ACS Mobility, we test all algorithms on the 50 American states and report the mean and standard deviation across all 50 target states. And in US Accident, we choose 13 American states with relatively high sample sizes in testing. The standard deviation here reflects the stability of performances across different target states.
Dataset Source State	ACS MOBILITY	US ACCIDENT
NY	CA	MS	PA	CA	FL	TX	MN
i.d.	o.o.d	i.d.	o.o.d	i.d.	o.o.d	i.d.	o.o.d	i.d.	o.o.d	i.d.	o.o.d	i.d.	o.o.d	i.d.
Base	LR	78.6	72.7 ±3.6	77.1	72.7 ±3.7	77.3	72.7 ±3.7	75.4	72.7 ±3.4	83.2	70.1 ±15.4	90.7	71.7 ±13.9	95.1	74.5 ±9.6	86.4	72.2 ±11.8
SVM	79.8	72.7 ±3.6	77.7	72.9 ±3.1	79.4	72.9 ±3.6	77.1	72.7 ±3.6	83.2	69.4 ±12.6	88.7	71.9 ±9.6	93.7	70.7 ±9.1	88.6	69.7 ±8.3
Methods	MLP	78.7	72.7 ±3.6	77.1	72.7 ±3.7	78.1	72.4 ±3.3	75.9	73.0 ±3.1	84.7	75.7 ±10.7	92.7	78.2 ±8.7	94.9	73.0 ±9.9	88.9	74.0 ±10.2
Tree Ensemble Methods	Random Forest	80.4	74.0 ±3.1	79.0	74.1 ±3.1	80.6	73.5 ±3.4	78.6	74.3 ±3.0	86.6	77.9 ±7.8	93.5	84.4 ±10.1	95.2	84.4 ±9.9	91.6	82.0 ±5.7
LightGBM	80.6	74.6 ±2.8	78.7	74.1 ±2.8	80.0	72.9 ±2.9	78.6	74.7 ±2.5	87.1	79.1 ±7.8	93.3	84.3 ±9.8	95.4	84.3 ±10.0	92.2	80.9 ±5.4
XGBoost	80.4	74.6 ±3.0	0.79	74.5 ±2.8	80.9	73.5 ±3.0	79.0	74.3 ±2.4	87.1	79.8 ±7.6	94.6	82.6 ±9.3	95.3	84.4 ±9.9	92.5	79.6 ±5.4
DRO Methods	x²-DRO	78.5	72.7 ±3.6	77.5	72.9 ±3.4	76.8	72.7 ±3.5	76.0	73.1 ±3.3	84.4	77.3 ±9.3	92.6	73.4 ±12.6	95.0	74.6 ±9.1	89.0	72.3 ±10.4
CVaR-DRO	78.6	72.6 ±3.5	77.2	72.8 ±3.5	77.7	72.6 ±3.7	75.7	73.3 ±3.2	84.7	74.5 ±10.3	92.7	74.4 ±11.4	95.0	74.9 ±9.4	89.5	73.4 ±10.0
x²-DORO	78.6	72.6 ±3.6	77.8	72.8 ±3.3	77.1	72.7 ±3.7	75.3	72.7 ±3.7	84.7	72.9 ±11.5	92.3	77.6 ±8.9	94.3	74.3 ±9.6	87.6	74.7 ±8.7
CVaR-DORO	78.7	72.7 ±3.6	78.0	73.6 ±3.1	77.4	72.7 ±3.7	75.3	72.7 ±3.6	84.9	74.1 ±10.5	92.8	74.4 ±11.2	94.9	74.7 ±9.5	89.1	74.1 ±9.5
Group DRO	78.6	72.5 ±3.4	77.1	72.7 ±3.6	76.0	72.7 ±3.7	76.0	72.8 ±3.2	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Imbalanced Learning Methods	SUBY	78.2	72.7 ±3.5	76.3	72.5 ±3.6	76.6	70.0 ±2.8	74.7	69.5 ±2.0	86.5	85.4 ±7.3	93.7	84.6 ±10.0	95.2	84.4 ±9.9	91.8	83.8 ±6.6
RWY	78.5	72.7 ±3.6	76.7	72.7 ±3.6	76.5	72.2 ±3.4	74.5	72.6 ±3.7	86.9	82.2 ±7.1	93.4	84.5 ±10.2	95.3	84.3 ±10.0	92.5	81.1 ±5.4
SUBG	80.2	74.3 ±2.9	79.2	74.2 ±2.8	79.5	72.5 ±2.9	78.6	74.3 ±2.7	86.3	81.0 ±7.3	93.0	83.8 ±9.9	95.1	84.4 ±9.9	91.1	80.1 ±5.8
RWG	80.3	74.6 ±3.0	79.1	74.4 ±2.8	80.1	73.3 ±2.9	78.7	74.2 ±2.6	87.5	79.7 ±7.5	93.4	83.8 ±9.4	95.2	84.4 ±9.9	92.4	79.3 ±5.3
JTT	78.3	72.7 ±3.6	76.5	72.4 ±3.7	77.6	71.5 ±2.6	75.1	70.7 ±2.4	86.5	79.0 ±7.7	92.7	83.6 ±9.5	94.9	84.3 ±9.9	91.8	78.2 ±5.6
DWR	79.7	74.2 ±3.1	78.3	73.9 ±2.9	79.1	72.9 ±2.9	77.5	74.0 ±2.6	87.2	79.8 ±7.7	93.4	83.7 ±9.9	95.3	84.4 ±9.9	92.3	78.5 ±5.8
Fairness Methods	DP	80.5	74.7 ±2.8	78.8	74.2 ±2.9	80.0	73.8 ±3.1	78.3	74.0 ±2.6	86.6	79.7 ±7.5	92.8	83.9 ±9.5	94.8	84.3 ±9.9	91.9	81.9 ±5.8
EO	80.3	74.7 ±2.8	78.9	74.1 ±2.8	79.8	73.4 ±3.0	78.5	73.9 ±2.7	86.6	79.5 ±7.5	93.2	84.4 ±9.6	95.2	84.4 ±10.1	92.2	79.6 ±5.4
EP	80.3	74.7 ±2.8	78.9	74.1 ±3.0	80.1	74.0 ±3.0	78.4	74.1 ±2.7	87.0	80.3 ±7.5	93.3	84.2 ±9.9	95.1	84.4 ±10.0	91.9	79.6 ±5.2
Exp	80.5	74.8 ±2.9	78.9	74.1 ±2.9	81.0	73.9 ±2.9	78.4	74.3 ±2.6	85.9	78.6 ±7.3	90.1	82.3 ±9.1	93.1	81.6 ±9.6	86.3	80.4 ±6.0
Threshold	80.5	74.5 ±2.9	78.6	74.3 ±2.8	78.2	71.9 ±2.9	78.5	73.9 ±2.6	84.3	77.8 ±7.3	88.1	79.9 ±7.9	91.2	79.9 ±9.3	82.0	75.7 ±4.8