GGFI 1: Methodology
The Global Green Finance Index (GGFI) 1 assesses ratings for financial centres calculated by a ‘factor assessment model’ that uses two distinct sets of inputs:
Not all financial centres will be represented in all the external sources, and the statistical model will take account of these gaps.
For the first edition of GGFI, analysis has been carried out on a range of financial centres across the world. Responses were collected via an online questionnaire which runs continuously. A link to this questionnaire is emailed to our growing list of respondents, which includes green finance professionals and experts, at regular intervals.
In order to avoid home centre bias, the centre where a respondent is based in is excluded from the assessment.
The financial centre assessments and instrumental factors are used to build a predictive model of green financial centres using a support vector machine (SVM).
SVMs are based upon statistical techniques that classify and model complex historic data in order to make predictions on new data. SVMs work well on discrete, categorical data but also handle continuous numerical or time series data. The SVM used for GGFI provides information about the confidence with which each specific classification is made and the likelihood of other possible classifications.
A factor assessment model is then built using the centre assessments from responses to the online questionnaire. The model predicts how respondents would have assessed centres with which they are unfamiliar by answering questions such as:
If a respondent gives Singapore and Sydney certain assessments then, based on the instrumental factors for Singapore, Sydney and Paris, how would that person assess Paris?
Predictions from the SVM are re-combined with actual financial centre assessments (except those from the respondents’ home centres) to produce the GGFI – a set of green financial centre ratings of green finance penetration and quality.
Over time, GGFI will be dynamically updated, either by updating and adding to the instrumental factors or through new green financial centre assessments. These updates will permit, for instance, a recently changed low carbon index to affect the rating of the centres.
The process of creating the GGFI is outlined diagrammatically below:
The strengths of this approach are:
A wide range of indices can be used for each instrumental factor;
Part of the process of building the GGFI will be sensitivity testing to changes in instrumental factors, the refining of the questionnaire, the development of the rating community and testing of the accuracy of predictions given by the SVM against actual assessments.