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.,,,