ntics><mrow><mi>j</mi><mo>=</mo><mn>1</mn><mo>,</mo><mi>…</mi><msub><mi>J</mi><mi>k</mi></msub></mrow><annotation encoding="application/x-tex">j = 1, \dots J_k</annotation></semantics></math>
systematically differ from the district-level effect, with the variance
of the study effects from the district-level effect summarized with
heterogeneity
<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><msub><mi>τ</mi><mi>w</mi></msub><annotation encoding="application/x-tex">\tau_{w}</an