Table S2.
Balance test by message type
| Indicator | Control | Placebo | Text | Voice | Crash | Injury | Joint orthogonality (P value) |
| Vehicle attributes | |||||||
| Share with license KA…* | 0.583 | 0.567 | 0.561 | 0.552 | 0.572 | 0.581 | 0.315 |
| (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… | 0.416 | 0.433 | 0.438 | 0.447 | 0.427 | 0.418 | 0.318 |
| (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-N | 0.113 | 0.122 | 0.119 | 0.122 | 0.107 | 0.121 | 0.655 |
| (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-S | 0.006 | 0.009 | 0.015 | 0.006 | 0.008 | 0.009 | 0.027 |
| (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 claim† | 0.152 | 0.170 | 0.169 | 0.178 | 0.204 | 0.173 | 0.001 |
| (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 claim | 0.078 | 0.077 | 0.079 | 0.083 | 0.099 | 0.074 | 0.054 |
| (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 claim | 0.015 | 0.016 | 0.011 | 0.017 | 0.019 | 0.017 | 0.446 |
| (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 accident | 2.563 | 1.938 | 1.693 | 1.940 | 1.755 | 1.711 | 0.000 |
| (0.211) | (0.141) | (0.089) | (0.164) | (0.097) | (0.142) | ||
| [0.015] | [0.000] | [0.018] | [0.000] | [0.001] | |||
| Annualized accident rate | 0.079 | 0.097 | 0.093 | 0.106 | 0.119 | 0.098 | 0.000 |
| (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 rate | 0.175 | 0.229 | 0.281 | 0.284 | 0.290 | 0.247 | 0.000 |
| (0.008) | (0.010) | (0.010) | (0.010) | (0.010) | (0.010) | ||
| [0.000] | [0.000] | [0.000] | [0.000] | [0.000] | |||
| N | 2,093 | 1,759 | 1,950 | 1,998 | 1,983 | 1,954 |
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.