Modelling Aging Population in Sri Lanka

Abstract

Population ageing is a universal phenomenon and it is expected to be among the most prominent global demographic trends of the 21st century. In Sri Lanka, there was a rising trend of aging population throughout the past years and has recorded the highest number of old people in South Asia. However, no sound statistical or mathematical models exist to project aging population in Sri Lanka. Using the population of people aged 60 years and above in Sri Lanka during 1950-2016, three types of statistical models: (i) ARIMA (0, 2, 1), (ii) exponential trend model, and (iii) double exponential smoothing model were developed. The models were compared using various statistical indicators and some statistical diagnostics tests. The comparison was done for both training set as well as a validation set. Among these models, the double exponential smoothing model was found to be the best. According to the forecast derived from this model, it was found that the increasing trend of aging population in the country will continue in the future and there will be approximately 2,936,000 old people in Sri Lanka in 2020. The information forecast in this study is beneficial for planners and decision makers in the government sector and other relevant organizations to cater to the needs of the increasing aged population.