Final answer:
A key pull factor attracting immigrants to Eastern European nations is the promise of wage-earning work and economic opportunities. The demand for cheap labor and the relative standard of living in these countries also contribute to this trend.
Step-by-step explanation:
One significant pull factor that has led many immigrants to Eastern European nations in recent decades is the promise of consistent, wage-earning work. Highly industrialized countries in Western Europe often offer more in terms of economic opportunities, with the core-periphery spatial relationship creating push-pull forces of migration based on these opportunities and advantages. Eastern Europe has experienced a need for cheap labor, which coupled with higher standards of living compared to some countries, acts as a strong incentive for migration.