<p>Additional file 1</p><p>Appendix A: Descriptive statistics of multi-child sample by parents’ country of origin, 1989-2011</p><p>Female Oldest Individuals Family Sibling Observations Africa 50% 42% 3,238 1,242 East Africa 49% 33% 2,857 1,209 Iraq 49% 31% 2,074 918 Iran 49% 28% 2,625 1,243 Lebanon 50% 40% 4,125 1,623 Turkey 50% 24% 12,742 4,520 Asia/Oceania 49% 28% 11,964 4,699 Chile 50% 32% 2,875 1,291 South America 46% 31% 1,227 542 non-EU 27 51% 37% 901 395 Europe Former 49% 41% 9,740 4,346 Yugoslavia Former Soviet 48% 41% 3,591 1,635 Union/Poland North America 51% 42% 489 216 EU 27 49% 37% 7,366 3,238 Nordic 49% 42% 26,022 11,019 Source: SIPP, 1989-2011 Appendix B: Results on effects of PYSM on Swedish performance with family fixed-effects by family size (reference=“No Pass”)</p><p>Test family Test family Test family Class family Class Family Class family size 2 size 3 size 4 + size 2 size 3 size 4+ Pass 1.21** 1.17** 1.18** 1.15** 1.19** 1.23** PYSM (.04) (.02) (.03) (.01) (.01) (.01)</p><p>Pass with 1.26** 1.20** 1.23** 1.22** 1.28** 1.30** distinction (.05) (.03) (.03) (.02) (.01) (.01) PYSM</p><p>Pass with highest 1.24** 1.16** 1.16* 1.33** 1.28** 1.25** distinction (.08) (.05) (.07) (.02) (.02) (.02) PYSM</p><p>Observations 12,314 8,532 4,446 47,372 40,140 23,977 Pseudo R-squared .07 .06 .06 .14 .13 .14 Notes: In addition, each regression also includes control variables for sex and firstborn status</p><p>Source: SIPP, 1989-2011</p><p>Exponentiated coefficients; Standard errors in parentheses</p><p>+ p<0.10, * p<0.05, ** p<0.01 Appendix C: Characteristics of those included in Swedish analyses versus not</p><p>Teacher Assigned Grades, 1989-2011 Proportion Average GPA Average PYSM Obs. Parents’ Country of Out of In the Out of In the Out sample (within In sample Origin Sample Sample sample sample variance) (within variance) Africa 34 66 -.29 -.14 10.7 (2.1) 11.8 (3.0) 3,724 East Africa 40 60 -.21 -.13 4.8 (1.6) 5.8 (2.1) 3,611 Iraq 48 52 -.29 -.17 3.8 (1.7) 5.3 (2.3) 3,496 Iran 49 51 .16 .22 5.1 (2.1) 6.2 (2.3) 4,709 Lebanon 37 63 -.53 -.49 4.3 (1.7) 5.2 (2.1) 4,894 Turkey 32 68 -.51 -.25 8.4 (2.7) 9.5 (3.4) 14,118 Asia/Oceania 35 65 .05 .08 6.9 (2.1) 8.5 (2.7) 14,261 Chile 47 53 -.51 -.44 5.0 (2.1) 5.7 (2.4) 4,092 South 47 52 -.19 -.07 6.7 (2.2) 7.3 (2.5) 1,723 America non-EU 27/ 42 58 .13 .21 10.6 (2.3) 11.9 (2.9) 1,120 Czech/Slovakia Former 43 57 -.14 -.12 10.8 (2.2) 11.7 (2.7) 13,277 Yugoslavia Former Soviet 44 56 .23 .28 8.5 (2.2) 9.7 (2.6) 4,435 Union/Poland North 49 51 -.19 -.03 7.5 (1.9) 10.4 (2.2) 706 America EU 27 41 59 .02 .07 11.9 (2.5) 12.6 (2.6) 8,479 Nordic 39 61 -.27 -.21 12.4 (2.4) 14.2 (3.0) 20,202 Total 39 61 -.20 -.12 9.3 (2.2) 10.6 (2.8) 111,847</p><p>National Standardized Test, 2005-2011 Proportion Average GPA Average PYSM Obs. Parents’ Country of Out of In the Out of In the Out sample In Sample Origin sample sample sample Sample (within variance) (within variance) Africa 48 52 -0.23 -0.15 11.6 (1.4) 12.5 (1.5) 1,907 East Africa 47 53 -0.18 -0.16 4.9 (1.2) 5.4 (1.3) 2,777 Iraq 55 45 -0.30 -0.10 4.0 (1.2) 5.9 (1.3) 2,637 Iran 48 52 0.14 0.18 6.4 (1.4) 6.5 (1.5) 2,920 Lebanon 45 55 -0.53 -0.48 4.9 (1.4) 5.2 (1.5) 3,691 Turkey 46 54 -0.32 -0.17 11.4 (1.5) 12.2 (1.6) 5,005 Asia/Oceania 46 54 0.02 0.05 7.7 (1.3) 8.8 (1.5) 8,132 Chile 50 50 -0.51 -0.52 6.8 (1.5) 7.1 (1.5) 2,117 South America 48 52 -0.11 -0.14 10.8 (1.3) 10.6 (1.4) 668 Non-EU 27 /Czech/ 51 49 -0.01 0.42 9.4 (1.8) 15.8 (1.3) 357 Slovakia Former Yugoslavia 50 50 -0.08 -0.12 8.7 (1.2) 10.6 (1.3) 6,150 Former Soviet 49 51 0.14 0.24 9.5 (1.4) 10.7 (1.4) 1,673 Union/Poland North America 48 52 -0.22 -0.10 8.2 (1.4) 10.1 (1.5) 420 EU 27 48 52 0.06 0.09 13.2 (1.4) 13.8 (1.4) 2,519 Nordic 45 55 -0.19 -0.13 18.1 (1.3) 19.2 (1.4) 6,161 Total 47 53 -0.16 -0.11 9.3 (1.3) 10.4 (1.4) 30,676 Source: SIPP, 1989-2011 Appendix D: Logistic regression on inclusion in Swedish national test/class grades analyses </p><p>Swedish Swedish Math Math National Class National Class Test Grade Test Grade Africa 1.07 1.36** 1.08 1.06 (.10) (.08) (.09) (.06)</p><p>East Africa 1.28** 1.31** 1.35** 1.06 (.11) (.08) (.11) (.07)</p><p>Iraq .91 .96 .89 .87* (.09) (.06) (.08) (.06)</p><p>Iran 1.13 .85** 1.10 .73** (.11) (.05) (.10) (.04)</p><p>Lebanon 1.41** 1.53** 1.38** 1.37** (.12) (.09) (.11) (.08)</p><p>Turkey 1.14+ 1.58** 1.28** 1.63** (.08) (.06) (.08) (.06)</p><p>Asia/Oceania 1.24** 1.46** 1.34** 1.33** (.08) (.05) (.08) (.05)</p><p>Chile 1.12 1.01 1.11 .82** (.11) (.06) (.10) (.05)</p><p>South America 1.08 .89 .91 .80** (.16) (.07) (.13) (.07)</p><p> non-EU 27/ .83 .90 .79 .87 Czech/Slovakia (.17) (.09) (.15) (.09)</p><p>Former Yugoslavia 0.97 0.96 0.94 0.89** (0.08) (0.03) (0.07) (0.03)</p><p>Former Soviet .94 .89* .97 .90+ Union/Poland (.10) (.05) (.09) (.05)</p><p>North America 1.07 .80+ .80 .64** (.19) (.10) (.14) (.08)</p><p>EU 27; non-Nordic 0.97 .94 1.00 .98 (.09) (.04) (.08) (.04)</p><p>Nordic Ref. Ref. Ref. Ref. Male Ref. Ref. Ref. Ref. Female .98 1.09** 0.99 1.00 (.02) (.01) (.02) (.01)</p><p>2009 or later Ref. - Ref. - Before 2009 .92** - 1.00 - (.02) (.02)</p><p>No Pass Ref. Ref. Ref. Ref. Pass .66** .75** 1.22** .82** (.03) (.02) (.05) (.02)</p><p>Pass with Distinction .93 1.04 1.43** 1.03 (.05) (.03) (.06) (.02)</p><p>Pass with Special 1.13* 1.61** 1.46** 1.31** Distinction (.07) (.06) (.08) (.04)</p><p>PYSM 1.02** 1.03** 1.02** 1.03** (.00) (.00) (.00) (.00)</p><p>1998 or Later - Ref. - Ref. Before 1998 - 1.09** - 1.51** (.02) (.03)</p><p>Observations 30,670 101,281 35,975 101,284 Pseudo R2 .01 .02 .01 .02 Notes: In addition, each regression also includes control variables for sex and firstborn status</p><p>Source: SIPP, 1989-2011</p><p>Exponentiated coefficients; Standard errors in parentheses; Family clustered standard errors</p><p>+ p<0.10, * p<0.05, ** p<0.01</p>