Measuring Activity—The Picture of Seniors in Poland and Other European Union Countries

Three interconnected and mutually supporting priority areas of “Europe 2020”, which will continue as priorities until 2030, constitute the idea of sustainable development based on three pillars—economic, environmental and social. The third pillar, related to social inclusion, aims to protect the interests of various social groups, including the growing group of elderly individuals. In this context, the activity of seniors becomes one of the key elements of sustainable development. For many years, it has been advocated that seniors have to be active, not only in terms of their physical activity, but also in terms of the so-called digital/technological inclusion or exclusion. This article attempts to answer the question of whether seniors’ activity in various areas of life (for example, taking into account the components of the Active Aging Index) can translate into a better assessment of their lives. We compare the activity of Polish seniors with their peers from EU countries. By identifying the differences, we try to pinpoint the causes of inactivity and indicate the areas of action necessary to stimulate their activity. Pointing out the disadvantages of the AAI’s construction, which are related to the cultural schemes, traditions, and social conditions of EU countries, we propose an original active aging indicator, which was created using Hellwig’s method and which is based on the results of a pilot study conducted with Polish seniors in 2020. The values of both indicators (AAI and the original) were also used to examine the impact of seniors’ activity on their general life satisfaction. In this part of the study, we used a comparative analysis and a classification method.