|Subgroup                      |   N| UW_mean|  UW_lo|  UW_hi| W_mean|   W_lo|   W_hi|
|:-----------------------------|---:|-------:|------:|------:|------:|------:|------:|
|Subject                       |    |        |       |       |       |       |       |
|Mathematics                   | 128|  -0.167| -0.188| -0.145| -0.164| -0.205| -0.122|
|Reading                       | 161|  -0.095| -0.113| -0.076|  -0.13| -0.169|  -0.09|
|Mixed                         |   2|   -0.07| -0.148|  0.008|  -0.07| -0.126| -0.015|
|School level                  |    |        |       |       |       |       |       |
|Primary                       | 196|  -0.122| -0.139| -0.104| -0.138| -0.168| -0.107|
|Secondary                     |  95|  -0.135| -0.162| -0.109| -0.153| -0.213| -0.094|
|Grade group                   |    |        |       |       |       |       |       |
|Early primary (1--4)          | 132|  -0.119|  -0.14| -0.098| -0.144| -0.186| -0.102|
|Middle (5--8)                 | 149|  -0.128| -0.149| -0.108| -0.132|  -0.17| -0.093|
|Secondary (9+)                |  10|   -0.19| -0.283| -0.097| -0.199| -0.312| -0.086|
|Sample size                   |    |        |       |       |       |       |       |
|Small (<10k)                  |  74|  -0.151| -0.192| -0.111| -0.202| -0.267| -0.138|
|Medium (10k--100k)            | 118|  -0.108| -0.126| -0.091| -0.094| -0.115| -0.074|
|Large (>100k)                 |  99|  -0.129|  -0.15| -0.107| -0.131|  -0.17| -0.092|
|Country                       |    |        |       |       |       |       |       |
|United States                 | 149|  -0.136| -0.153|  -0.12| -0.142| -0.166| -0.117|
|United Kingdom                |  58|  -0.128| -0.151| -0.104| -0.136| -0.165| -0.107|
|Netherlands                   |  27|  -0.146| -0.198| -0.093|  -0.14| -0.187| -0.093|
|Other countries               |  57|  -0.089| -0.138| -0.039| -0.147| -0.207| -0.086|
|Source tier                   |    |        |       |       |       |       |       |
|Tier 1: Peer-reviewed         |  62|   -0.11| -0.157| -0.062| -0.165| -0.233| -0.098|
|Tier 2: Working paper         |  65|  -0.132| -0.164|   -0.1|  -0.13| -0.164| -0.096|
|Tier 3: Gov't / institutional |  34|   -0.12| -0.156| -0.084| -0.122| -0.165| -0.079|
|Tier 4: Commercial            | 130|  -0.133| -0.148| -0.118| -0.138| -0.163| -0.113|
|All estimates                 | 291|  -0.126| -0.141| -0.112| -0.142|  -0.17| -0.115|
