Bulgaria is projected to experience a 22.5% population decrease, falling from 6.9 million in 2020 to 5.4 million in 2050. The primary factor driving this decline is significant outbound migration from the country.

Lithuania's population is anticipated to contract by 22.1% in the coming thirty years, dropping from 2.7 million to 2.1 million individuals. Similar to Bulgaria, Lithuania's most significant population decline results from substantial emigration.

Latvia is bracing for a 21.6% reduction in its population from 2020 to 2050. Since its entry into the European Union in May 2004, Latvia has seen approximately a one-fifth decline in its population. This decrease is primarily attributed to economic migration and a low birth rate.

Ukraine is expected to witness a 19.5% decline in its population, falling from 43.7 million in 2020 to 35.2 million in 2050. This population loss is attributed to a combination of factors, including significant emigration rates, elevated mortality rates, and subdued birth rates. Specifically, the birth rate in the country stands at 9.2 births per 1,000 people, while the death rate is 15.2 deaths per 1,000 people.

Serbia's population is anticipated to decrease from 8.7 million to 7.1 million in the next three decades, marking an approximately 18.9% decline. The departure of many highly educated and skilled workers seeking better job prospects, coupled with the scarcity of such opportunities in Serbia, contributes significantly to the high migration rates. This population decrease is further exacerbated by low fertility rates in the country.

The population is expected to contract by 18.2%, decreasing from 3.3 million in 2020 to 2.7 million in 2050. Bosnia and Herzegovina faces a fertility rate of 1.26 births per woman, significantly lower than the population replacement rate of 2.1 births per woman.

Croatia anticipates a population reduction of 18.0%, with numbers forecasted to decrease from 4.1 million to 3.4 million in the next three decades. The population achieved its highest point in 1991 at 4.78 million but has been on a declining trajectory since, primarily due to low birth rates and an increasingly aging population.

Moldova is poised to experience a 16.7% population decrease between 2020 and 2050. The population is estimated to decrease by 600,000, dwindling from 4 million to 3.4 million. Factors such as poverty and corruption have compelled many highly-skilled, young workers to leave the country, while the aging population grapples with subpar living conditions and elevated mortality rates.