1. Lab Eight Econ 240C

2. Per Se Legislation Introduced in Great Britain in October 1967 Before driving dangerously while intoxicated led to a conviction only if you were found guilty in court After October 1967, if your blood alcohol content, BAC, was 0.08 or greater you were per se guilty

3. Capturing an event with a step function No visual impact

4. Two Approaches to Seasonal Data Regression of kill(t) = a –b*step(1967.10) + seasonal dummies + e(t)

5. Regression with Seasonal dummies

7. Actual, fitted, residual

13. The Alternative Approach Box Jenkins –Seasonal difference instead of seasonal dummies Model: Kill(t) c ar(1) ar(2) ar(3) step (1-Z 12 ) Kill(t) c ar(1) ar(2) (1-Z 12 ) step(1967.10) Sdkill(t) c ar(1) ar(2) sdstep(1967.10)

14. Seasonal difference

19. Residual is White Noise