Table 3: Definitions of Intervention Variables
Table 3: Definitions of Intervention Variables
| Name | Definition | Facts | Affected variables |
|---|---|---|---|
| EASTER | 1 in Easter months, 0 otherwise | Easter effects | All |
| DAYS | Trading days per month | Trading day effects | All |
| Mar-89 | 1 in 1989:3, 0 otherwise | Strike in bus mode and large increase in single-ticket prices | SMT, 10MT |
| Mar-90 | 1 in 1990:3, 0 otherwise | Strike in bus mode | SMT, SBT, 10BT |
| Apr-90 | 1 in 1990:4, 0 otherwise | Strike in bus mode and large increase in single-ticket prices | 10MT, 10BT |
| Jan-91 | 1 in 1991:1, 0 otherwise | Strike in Metro mode and large increase in single-ticket prices | SMT |
| Apr-91 | 1 in 1991:4, 0 otherwise | Strike in Metro mode | SMT |
| Feb-92 | 1 in 1992:2, 0 otherwise | Strike in bus mode | SMT, SBT, 10BT |
| Mar-92 | 1 in 1992:3, 0 otherwise | Strike in bus mode | SBT, 10BT |
| Apr-92 | 1 in 1992:4, 0 otherwise | Consequences of bus strikes | SBT |
| Jan-98 | 1 from 1998:1, 0 otherwise | Introduction of the Metrobus ticket | SMT, SBT |
| Feb-93 | 1 in 1993:2, 0 otherwise | ? | JTC |
| Apr-93 | 1 in 1993:4, 0 otherwise | Metro service interruption | JTC |
| Apr-93 | 1 in 1993:4, 0 otherwise | Temporary closing of certain lines | |
| Mar-94 | 1 in 1994:3, 0 otherwise | ? | TC, JTC |
| Jul-95 | 1 in 1995:7, 0 otherwise | ? | JTC |
Key: ? = no known explanation for this intervention variable.