Table 2: Hazard Models of Montreal Protocol Amendment Ratification

||||_Depen_<br>|_dent variable: Ra_<br>|_tification H_<br>|_azard Rate_<br>|||
|---|---|---|---|---|---|---|---|---|
||L|ondon|Cop|enhagen|M|ontreal||eijing|
||(1)|(2)|(3)|(4)|(5)|(6)|(7)|(8)|
|CumulativeRTAs|0.307<sup>_∗∗∗_</sup><br>(0.098)|0.376<sup>_∗∗∗_</sup><br>(0.022)|0.130<sup>_∗∗_</sup><br>(0.056)|0.286<sup>_∗∗∗_</sup><br>(0.018)|0.046<sup>_∗_</sup><br>(0.027)|0.475<sup>_∗∗∗_</sup><br>(0.017)|0.075<sup>_∗∗∗_</sup><br>(0.024)|0.395<sup>_∗∗∗_</sup><br>(0.015)|
|Cumulative MP/ODS Prov|0.260<br>(0.279)|0.203<sup>_∗∗∗_</sup><br>(0.059)|0.292<br>(0.338)|1.032<sup>_∗∗∗_</sup><br>(0.054)|0.096<br>(0.138)|0.752<sup>_∗∗∗_</sup><br>(0.040)|0.150<br>(0.224)|0.571<sup>_∗∗∗_</sup><br>(0.034)|
|Observations|1,313|1,313|1,443|1,443|1,289|1,289|1,319|1,319|
|Model|Cox|PPML|Cox|PPML|Cox|PPML|Cox|PPML|
|Baseline Hazard|year|country,year|year|country,year|year|country,year|year|country,year|

Hazard model coefficient estimates of Montreal Protocol and Montreal Protocol amendment ratification. Cumulative RTAs is the time-varying cumulative number of RTAs that a country has signed. Cumulative MP/ODS Provisions are the cumulative number of signed RTAs that include our study provisions on ODS and/or Montreal Protocol compliance. Cox proportional hazard models include time-invariant World Bank country income categories (high, low, upper middle, lower middle), region categories (EAS, ECS, EU28, LCN, MEA, NAC, SAS, SSF), and Montreal Protocol Article 5 membership status. Censored psuedo-poisson maximum likelihood (PPML) models estimate Poisson-equivalent regressions and include linear country and year fixed effects which are equivalent to countryspecific baseline hazard functions. We report two-way cluster-robust standard errors clustered at the country and year level for all regressions. Statistical significance from two-sided _t_ tests are denoted by<sup>_∗_</sup> p _<_ 0.1;<sup>_∗∗_</sup> p _<_ 0.05;<sup>_∗∗∗_</sup> p _<_ 0.01.

Table 3: Deviation from Montreal Protocol Targets after RTA Signature

|||_Dep_|_endent variab_|_le: IHS Targ_|_et Deviation_|||
|---|---|---|---|---|---|---|---|
||CFCs|Halons|CFCs (B)|CTC|TCA|HCFCs|MB|
||(1)|(2)|(3)|(4)|(5)|(6)|(7)|
|Post Sig|0.696<sup>_∗∗∗_</sup><br>(0.154)|0.371<sup>_∗∗∗_</sup><br>(0.094)|0.021<br>(0.039)|0.139<br>(0.102)|0.022<br>(0.052)|_−_0.396<sup>_∗∗∗_</sup><br>(0.083)|_−_0.024<br>(0.106)|
|Post_×_ODS|_−_1.401<sup>_∗∗∗_</sup><br>(0.381)|_−_0.381<sup>_∗∗_</sup><br>(0.190)|_−_0.043<br>(0.078)|_−_0.434<sup>_∗_</sup><br>(0.251)|_−_0.287<sup>_∗_</sup><br>(0.170)|_−_0.005<br>(0.212)|0.023<br>(0.280)|
|Observations|6,118|6,118|6,118|6,118|6,118|6,118|6,118|
|R<sup>2</sup>|0.526|0.551|0.390|0.484|0.602|0.642|0.528|
|Mean(ODP tons)|-1402|-261|-3|-551|-30|-116|14|

FE triple-difference regressions on a stacked country-level panel with a _±_ 3 year event window around RTA signature. All outcomes are the inverse hyperbolic sine of the difference between ODS emissions and emissions targets under the Montreal Protocol. All models include country-event fixed effects. Robust standard errors are (two-way) clustered at the country-event and country-year levels. We report the mean deviation from target across the entire sample in tons of ozone depletion potential (ODP). Statistical significance from two-sided _t_ tests are denoted by<sup>_∗_</sup> p _<_ 0.1; _∗∗_ p _<_ 0.05; _∗∗∗_ p _<_ 0.01.

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