This paper investigated the relationships between the best-practice and the greatest possible life expectancies by means of gaps, lags and decomposition analyses, from 1950–1955 up to 2095–2100. The data were gathered from the United Nations’ World Population Prospects (2017), containing abridged period life tables, for both sexes combined, for 201 countries or areas, which allowed the identification of low-mortality regions that are sometimes omitted in previous studies. It was observed that both best-practice and greatest possible life expectancies rose and are expected to continue to rise linearly in a very similar way. Moreover, the average gap between the best-practice and the greatest possible life expectancies was of about 1.14 years and the average lag was 7.59 years. Finally, it was found that major contributions to the gap are typically due to age groups beyond 65 years.

中文翻译：

---

最佳实践与最大可能预期寿命之间的关系。

本文通过差距、滞后和分解分析，研究了 1950 年至 1955 年至 2095 年至 2100 年的最佳实践与最大可能预期寿命之间的关系。这些数据来自联合国的《世界人口展望》（2017 年），其中包含 201 个国家或地区的男女合并的简略周期生命表，从而可以识别出在以前的研究中有时会被忽略的低死亡率地区。据观察，最佳实践和最大可能的预期寿命均有所上升，并且预计将以非常相似的方式继续线性上升。此外，最佳实践与最大可能预期寿命之间的平均差距约为 1.14 年，平均滞后时间为 7.59 年。最后，