Predicting Indonesian Democracy Index in Yogyakarta Province as Time Series Data using Exponential Smoothing

Indonesian government developed a benchmark used to quantify the development of democracy in Indonesia, which is called as the Indonesian Democracy Index (IDI). IDI reflects aspects that include Civil Liberty, Political Rights, and Institution of Democracy. Over the past 10 years, the development of IDI in the Special Region of Yogyakarta has fluctuated. This paper tried to predict the value of IDI in Yogyakarta Province, using IDI of Yogyakarta Province data for the past 10 years available from Indonesian Central Statistics Agency by exponential smoothing method. 9 variations of smoothing parameter a are used in this paper, from a value of 0.1 until 0.9, increased by 0.1. The models are evaluated in terms of robustness using Root Mean Square Error (RMSE) and accuracy using Mean Average Percentage Error (MAPE). The smallest RMSE and MAPE values is obtain from a model with α = 0.9, with RMSE = 4.445859453 and MAPE = 4.11%, while the worst model indicated with the highest RMSE and MAPE values used alpha = 0.1.