Growth Curve of Socio-economic Development in North-Eastern Tribes

Socio-economic status of north-eastern tribes in India has relevance to formulate developmental policies for the region. The present investigation conducted on north-eastern (NE) tribes via questionnaires and descriptive interviews in a socio-economic survey is related to personal and social events over a long span of time interval focused on NE tribal lifestyle. Investigation by retrospective longitudinal study is of interest in lifestyle and socio-economic assessment for individuals when relevant data on past are not recorded. For tribal individuals selected by stratified random sampling from Tripura, India, we record descriptive-type and question-answer-type response on their past and present standard of living. For each individual and for variables related to development, viz. income, hygiene, food, shelter, clothing, entertainment, education, medical facilities, social environment and human resources, over a time period around a specific time of past/present, we consider measurement of each of these variables in a Likert-type scale to obtain consolidated status scores for comparison over time. Scores on status are then analysed for detecting possible trend in living standard of tribal individuals with progress of time. Over a time range spanning for about last 60 years from 2013, the events reported in this study reveal an upward ascending movement of social change from past to present in terms of increasing composite status score. Growth curves of scores obtained by nonparametric regressions indicate general improvement of tribal welfare status with progress of time. The curves show upward trend in growth, which is faster towards the end. Proliferation rate of scores suggests that much of the changes in a scaled speed of improvement in status are relatively recent phenomena at the year 2013. Composite status scores are based on discrete scores of individual components. Under appropriate assumptions, characterization theorems are obtained from solution of Cauchy equations for discrete random variables relevant in modelling status scores. These include discrete version of bi-exponential and normal distribution, extending the results of Dasgupta (Theory of Probability and Its Applications, 38(3):520–524, 1993).