(1)

(2)

(3)

(4)

(5)

(6)

A/national core sample

B/Shanghai

C/Floating population area

Mathematical achievement

a1/Native

a2/Outsiders

b1/Native

b2/Outsiders

c1/Native

c2/Outsiders

Communication frequency

−0.593**

0.421

1.122

1.453

0.217

−0.552

(0.203)

(0.552)

(0.708)

(1.090)

(0.263)

(0.447)

Relationship evaluation

1.390***

0.119

0.306

0.449

1.329***

1.544***

(0.173)

(0.545)

(0.568)

(1.022)

(0.230)

(0.417)

Sample size

3933

382

367

117

1884

550

1) Students who only include groups of rural households

Communication frequency

−0.769**

1.353

2.142

1.907

0.00817

−0.204

(0.260)

(0.753)

(3.157)

(2.208)

(0.515)

(0.627)

Relationship evaluation

1.352***

0.296

1.779

4.262

1.456***

1.454**

(0.217)

(0.675)

(2.497)

(2.725)

(0.429)

(0.557)

Sample size

Communication frequency

2598

217

28

37

548

340

2) Add control variables parent-child relationship variables (contact frequency and relationship

Communication frequency

−0.692**

0.319

1.366

−0.0323

0.328

−0.435

(0.225)

(0.626)

(0.758)

(1.249)

(0.286)

(0.511)

Relationship evaluation

1.256***

−0.345

0.417

0.148

1.117***

1.584***

(0.190)

(0.611)

(0.610)

(1.056)

(0.254)

(0.459)

Sample size

3488

333

351

110

1746

491