Parameters | The model of abrupt and permanent impact* | The model of gradual and permanent impact† | The model of abrupt and temporary impact‡ | |||
---|---|---|---|---|---|---|

Coefficient | p Value | Coefficient | p Value | Coefficient | p Value | |

*(1−B)Y_{t} = θ_{0}+(1−θ_{1}B)a_{t}+ωI_{t}, where Y_{t} is the value of the ratio at time t, and I_{t} is intervention dummy variable coded “0 = before intervention” and “1 = thereafter”. | ||||||

†(1−B)Y_{t} = θ_{0}+(1−θ_{1}B)a_{t}+[ω/(1−δB)]I_{t}, where Y_{t} is the value of the ratio at time t, and I_{t} is intervention dummy variable coded “0 = before intervention” and “1 = thereafter”. | ||||||

‡(1−B)Y_{t} = θ_{0}+(1−θ_{1}B)a_{t}+[ω/(1−δB)]I_{t}, where Y_{t} is the value of the ratio at time t, and I_{t} is intervention dummy variable coded “0 = before and after intervention” and “1 = at the moment of intervention”. | ||||||

θ_{0} | −0.000 | 0.875 | −0.000 | 0.885 | −0.000 | 0.809 |

θ_{1} | 0.382 | <0.001 | 0.382 | <0.001 | 0.375 | <0.001 |

ω | −0.001 | 0.641 | −0.001 | 0.640 | 0.000 | 0.672 |

δ | 0.344 | 0.832 | −0.993 | <0.001 | ||

Q_{6} | 0.81 | 0.976 | 0.80 | 0.977 | 0.63 | 0.986 |

Q_{12} | 2.24 | 0.998 | 2.24 | 0.998 | 2.29 | 0.997 |

Q_{18} | 6.57 | 0.988 | 6.63 | 0.988 | 6.63 | 0.988 |

Q_{24} | 25.78 | 0.312 | 25.71 | 0.314 | 26.62 | 0.272 |