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−θ_{16}B^{16})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−θ_{16}B^{16})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−θ_{16}B^{16})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 | 0.187 | −0.000 | 0.215 | −0.000 | 0.256 |

θ_{1} | 0.227 | 0.004 | 0.219 | 0.005 | 0.221 | 0.005 |

θ_{16} | −0.291 | <0.001 | −0.283 | 0.005 | −0.275 | 0.001 |

ω | 0.007 | 0.118 | 0.007 | 0.106 | 0.008 | 0.081 |

δ | −0.231 | 0.697 | 0.734 | 0.104 | ||

Q_{6} | 6.03 | 0.197 | 6.95 | 0.138 | 6.79 | 0.147 |

Q_{12} | 16.53 | 0.085 | 17.60 | 0.062 | 17.19 | 0.070 |

Q_{18} | 18.56 | 0.292 | 19.98 | 0.221 | 20.04 | 0.218 |

Q_{24} | 29.43 | 0.133 | 30.40 | 0.109 | 30.15 | 0.115 |