Table 2.

Effects of Age, Average Grades and Family Socioeconomic Backgrounds on Friendship Choice

	Best-friend nomination			Ordered nominations			Unordered nominations
	E1	G1	D1	E2	G2	D2	E3	G3	D3
Panel A: Female-Female nominations
Age difference
alter < ego	0.339	0.626	0.585	0.342	0.637	0.594	0.338	0.629	0.587
alter > ego	0.347	0.66*	0.621*	0.351	0.67*	0.628*	0.347	0.662*	0.622*
GPA difference
alter < ego	0.605	0.623	0.626	0.609	0.626	0.629	0.606	0.623	0.626
alter > ego	0.609	0.625	0.625	0.628	0.646	0.647	0.622	0.639	0.640
SES difference
alter < ego	0.928	0.930	0.931	0.925	0.927	0.928	0.923	0.926	0.926
alter > ego	0.962*	0.963*	0.965*	0.966*	0.966*	0.967*	0.964*	0.966*	0.966*
Observations		472,215			480,215			473,095
Panel B: Male-Male nominations
Age difference
alter < ego	0.390	0.674	0.622	0.388	0.668	0.619	0.384	0.662	0.612
alter > ego	0.424*	0.747*	0.69*	0.425*	0.746*	0.69*	0.422*	0.741*	0.684*
GPA difference
alter < ego	0.648	0.664	0.667	0.642	0.658	0.661	0.639	0.653	0.656
alter > ego	0.742*	0.757*	0.756*	0.75*	0.767*	0.765*	0.747*	0.761*	0.76*
SES difference
alter < ego	0.952	0.956	0.957	0.954	0.959	0.960	0.953	0.957	0.958
alter > ego	0.973*	0.977*	0.978*	0.981*	0.985*	0.986*	0.98*	0.984*	0.985*
Observations		388,373			398,571			389,502

^aEstimates are presented in exponential form. All coefficients are statistically significant at 0.001 level.

^bAsterisk indicates that asymmetry is statistically significant at 0.001. That is, the coefficient of "alter > ego" dyads is significantly different from that of the "alter < ego" dyads.