How to Measure Years of Good Life

, by Simone Ghislandi - professore associato presso il Dipartimento di scienze sociali e politiche
Starting from the Sustainable Development Goals, a research team has identified the right metric to measure success by focusing on wellbeing and a demographic approach. There are two advantages of YoGL: it is possible to measure entire countries and subpopulations and to observe their variation over time

The Sustainable Development Goals (SDGs) are a wake-up call for humanity to move toward a more sustainable and inclusive development model. The SDG approach focuses on poverty and inequality reduction, well-being maximization and environmental sustainability, in an attempt to overcome the limits of GDP as the main indicator of success in the development of a country. Although comprehensible in theory, the metrics to be used for measuring the degree of SDG success are still debated.

Attempts at overall quantitative assessments of sustainable development can focus on either determinants or constituents of long-term human well-being. In this paper we focus on the constituents of well-being using a demographic approach. We construct a tailor-made metric based on life expectancy and indicators of objective and subjective well-being: Years of Good-Life (YoGL). The idea behind YoGL is to focus on the constituents of well-being and their changes over time. First and foremost, we consider survival as the most essential prerequisite for enjoying any quality of life. But since mere survival is not enough, we go on to define "good" years of life as those years spent above minimum levels of both objectively observable conditions and subjective life satisfaction. Only if people are above critical levels in these areas are their life years considered as good years in the calculation of YoGL. The three objective aspects YoGL considers are: being out of poverty; having no severe activity limitations; and being cognitively able to function. Having a positive life satisfaction, on the other hand, represents the subjective aspects of the index.
YoGl has two main advantages over other similar indicators: it can be measured across subpopulations (for example, gender) and across time. When YoGL is calculated on complete datasets such as the European Survey of Health, Ageing and Retirement in Europe (SHARE), all four aspects can be measured for the 50+ demographic.

Overall, northern European countries and Switzerland perform better than the Mediterranean and Eastern European countries. Even if Italy and Spain are traditionally associated with high life expectancy, they score low in both subjective well-being and in cognitive abilities, reducing on average the number of "good" years lived. Incidentally, these results might reflect the lower educational attainments among the elderly population for these countries.
YoGL can also be set up for ranking countries at world level. Data for this setting, although available, are not always complete and some technical adjustments are needed. Using the World Values Surveys, we show that strong inequalities exist across and within countries. For example, while YoGL for females in the top country (Sweden) is 58, the same figure for the last one (Yemen) is 10. In general, while the reduction in "good years" due to poor health plays a proportionally larger role in highly developed countries, elevated levels of poverty and cognitive impairment are the main drivers of losing YoGL for men in the least developed countries. Within countries, it is also clear that the difference between life expectancy and YoGL is higher for females than for males. This indicates that the objective and subjective limitations to a "good life" are not gender neutral.

The strong inequality patterns are concerning, but there are reasons for optimism. Looking at the changes over time of YoGL, it is evident that most countries witnessed significant increases over the last decades. In particular, in India the reduction in poverty prevalence and the improvement in physical health and in subjective well-being have increased YoGL of more than 50% in 25 years; more limited improvements have been registered in other middle-income countries like Mexico and South Africa.
This study only addresses a step in the great challenge to comprehensively develop a metric of well-being that can be assessed across subpopulations and over time. This is important because measurement is key in defining targets and driving policies. Also, this new metric can be used more widely in sustainability research. This is why, for example, the same research team is planning to develop models and scenarios with feedback from environmental changes onto future long-term human well-being.