Table S2.

Balance test by message type

IndicatorControlPlaceboTextVoiceCrashInjuryJoint orthogonality (P value)
Vehicle attributes
 Share with license KA…*0.5830.5670.5610.5520.5720.5810.315
(0.011)(0.012)(0.011)(0.011)(0.011)(0.011)
[0.300][0.142][0.043][0.477][0.871]
 Share with license KB…0.4160.4330.4380.4470.4270.4180.318
(0.011)(0.012)(0.011)(0.011)(0.011)(0.011)
[0.303][0.152][0.047][0.478][0.925]
 Share with license KBK-N0.1130.1220.1190.1220.1070.1210.655
(0.007)(0.008)(0.007)(0.007)(0.007)(0.007)
[0.392][0.504][0.378][0.586][0.427]
 Share with license KBP-S0.0060.0090.0150.0060.0080.0090.027
(0.002)(0.002)(0.003)(0.002)(0.002)(0.002)
[0.399][0.007][0.768][0.481][0.274]
Claims data
 Any previous claim0.1520.1700.1690.1780.2040.1730.001
(0.008)(0.009)(0.008)(0.009)(0.009)(0.009)
[0.128][0.134][0.024][0.000][0.070]
 Any previous injury claim0.0780.0770.0790.0830.0990.0740.054
(0.006)(0.006)(0.006)(0.006)(0.007)(0.006)
[0.905][0.942][0.579][0.018][0.576]
 Any previous fatality claim0.0150.0160.0110.0170.0190.0170.446
(0.003)(0.003)(0.002)(0.003)(0.003)(0.003)
[0.767][0.207][0.661][0.405][0.596]
 Number previous claims per accident2.5631.9381.6931.9401.7551.7110.000
(0.211)(0.141)(0.089)(0.164)(0.097)(0.142)
[0.015][0.000][0.018][0.000][0.001]
 Annualized accident rate0.0790.0970.0930.1060.1190.0980.000
(0.005)(0.006)(0.005)(0.006)(0.006)(0.006)
[0.013][0.037][0.000][0.000][0.008]
Attrition
Phase 1 attrition rate0.1750.2290.2810.2840.2900.2470.000
(0.008)(0.010)(0.010)(0.010)(0.010)(0.010)
[0.000][0.000][0.000][0.000][0.000]
N2,0931,7591,9501,9981,9831,954
  • Table covers only phase 1 vehicles, including both those that were found in phase 2 and those that were not. SEs in parentheses. P values comparing noncontrol groups with control group in brackets.

  • * Vehicle license plates are of the form KXX NNNX, where X represents a letter and N a number. KA… license plates were issued before KB… plates, and among KB… plates, KBK-N were issued before KBP-S.

  • Previous claims refer to claims recorded before recruitment.