Demographic forecasting of population projection in Greece: A Bayesian probabilistic study

Abstract Background Demographic aging is an emerging issue in Greece, characterized by low fertility and increased life expectancy. Undoubtedly, demographic aging is a challenge for public health not only due to the financing of public pensions, but also for the increasing utilization of health care. Methods The total fertility rate and life expectancy at birth are projected probabilistically using Bayesian hierarchical models and United Nations population data for Greece from the period of 1950 to 2015. These are then converted to age-specific mortality rates and combined with a cohort component projection model. This yields probabilistic projections of total population by sex and age groups, total fertility rate (TFR), female and male life expectancies at birth and potential support ratio PSR (persons aged 20-64 per person 65+) by the year 2100. Results The total population in Greece in 1950 was around 7.5 million, increasing to 11 million based on the 2011 population census but is projected to decline to 7.5 million at 2100. TFR has followed a strong downward trend with 1.4 children per woman in 2005-2010 and is projected to have a slight increase to 1.6 and 1.8 children per woman for 2050 and 2100 with all values being below the replacement-level fertility. Life expectancy is expected to increase to 84 years for men and 88 years for women in 2050, and 90 years for men and 94 years for women in 2100. PSR is expected to decline dramatically from 3 in 2011 to approximately 1.5 in 2050 and 2100. Conclusions Over the years, Greece has lost its youthful structure and has acquired the characteristics of an aging population, reflecting the population distribution of Western countries. Demographic aging is harmful for the economic growth, the social security system, the social assistance, and it is closely linked to national defense and public health. A long-term multidimensional program is recommended to confront the demographic issue based on the previous international experience. Key messages Total fertility rate will be below replacement level and potential support ratio will decline dramatically. A long-term multidimensional program needs to be developed to address the demographic aging.