Relationship Among the Diameter of the Area of Influence & Refill Usage of Sri Lanka Using Anonymized Call Detail Records

—Economic activity and human mobility are two of the three pillars of socioeconomic indicators and understanding how these correlate with each other is important to society as it may be useful in attempting to classify people into socioeconomic levels using call detail records. Refill usage is one of the key attributes that can taken to model socioeconomic levels as the general sense is that people who spend on more refill are considered as people with high purchasing power. This type of research on SES classification by CDR happened for first time in Sri Lanka and using refill features for modeling, also is not seen in any literature to date. This paper describes what the Diameter of Area of Influence (DAI) is and the relationship between the DAI of an individual which is one of many user mobility features that can be extracted from Call Detail Records (CDRs) and the amount the user refills which is the main economic activity that can be derived from CDRs. This paper also describes a methodology to find DAI using CDRs and how to cluster individual users using this distance.