[data] test: N=33913369, P=200, 交易日=24
  day 1/24 20260202 n=1415392 (8s)
  day 2/24 20260203 n=1439948 (14s)
  day 3/24 20260204 n=1423891 (20s)
  day 4/24 20260205 n=1440046 (30s)
  day 5/24 20260206 n=1428012 (39s)
  day 6/24 20260209 n=1421240 (47s)
  day 7/24 20260210 n=1419409 (56s)
  day 8/24 20260211 n=1414544 (65s)
  day 9/24 20260212 n=1414986 (73s)
  day 10/24 20260213 n=1421417 (99s)
  day 11/24 20260224 n=1394488 (108s)
  day 12/24 20260225 n=1413736 (117s)
  day 13/24 20260226 n=1413281 (139s)
  day 14/24 20260227 n=1422576 (158s)
  day 15/24 20260302 n=1422253 (167s)
  day 16/24 20260303 n=1413551 (176s)
  day 17/24 20260304 n=1429868 (185s)
  day 18/24 20260305 n=1424365 (193s)
  day 19/24 20260306 n=1417787 (202s)
  day 20/24 20260309 n=1224254 (210s)
  day 21/24 20260310 n=1419877 (218s)
  day 22/24 20260311 n=1424732 (229s)
  day 23/24 20260312 n=1425909 (241s)
  day 24/24 20260313 n=1427807 (250s)

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【Chow 可合并性检验 · H0: β_SH = β_SZ】
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  样本: SH n=21,427,350  SZ n=12,486,019  因子k=200
  RSS_pool=892802.1804  RSS_SH+RSS_SZ=890605.4893
  分组使RSS下降: 2196.6911 (0.246%)
  Chow F(200, 33912969) = 418.2341
  p值 = 0.000e+00
  → 拒绝H0(系数有差异)
  效应量: 分组仅降低RSS 0.246% —— 统计显著但经济幅度极小
