This paper studies long-term trends and patterns in global refugee migration. We explore the intensity, spread, and distance of refugee migration at a global, regional, and country level between 1951 and 2018. The analysis did not detect a long-term increase in the global intensity of refugee migration. Primarily depending on levels of conflict, refugee numbers have fluctuated at levels of between 0.1 and 0.3 percent of the world population. Apparent increases in numbers of the globally displaced are driven by the inclusion of populations and countries that were previously excluded from the data. While refugee populations continue to be concentrated in countries with low-to-medium income levels, the analysis reveals several geographic shifts in refugee migration. Refugees tend to come from a shrinking number of origin countries and move to an increasing variety of destination countries. This trend seems to reflect a concentration of recurrent conflict cycles in a relatively small number of countries and a parallel increase in the number of safe destinations. Although the vast majority of refugees remain near to origin countries, the average distance between origin and destination countries has increased over time, presumably linked to the greater ease of travel and migration-facilitating networks.

中文翻译：

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全球难民移民的趋势和模式

本文研究了全球难民迁移的长期趋势和模式。我们探讨了 1951 年至 2018 年间在全球、区域和国家层面上难民迁移的强度、分布和距离。该分析并未发现全球难民迁移强度的长期增加。主要取决于冲突的程度，难民人数在世界人口的 0.1% 到 0.3% 之间波动。全球流离失所人数的明显增加是由于将之前被排除在数据之外的人口和国家纳入其中。虽然难民人口继续集中在中低收入水平的国家，但分析揭示了难民迁移的几个地理变化。难民往往来自越来越少的原籍国，而转移到越来越多的目的地国。这一趋势似乎反映了在相对较少的国家中反复出现的冲突周期的集中，以及安全目的地数量的平行增加。尽管绝大多数难民仍然在原籍国附近，但原籍国和目的地国之间的平均距离随着时间的推移而增加，这可能与旅行和移民便利网络更加便利有关。