• Greece's abandoned "ghost" towns and villages offer an eerie glimpse into the future of a country, whose Prime Minister has warned of "existential" population collapse. 
• Years of decreasing births, economic hardship and mass emigration have left huge swathes of the country vacant.
• Economists warn that population decline is now putting a major strain on society – with not enough young workers to grow the economy and support the elderly.

Lasta, GREECE — There's nobody around anymore to man Saint George cafe in Lasta, a mountainous village in Greece's Peloponnese region.

Instead, there's an honor system — just take a drink, leave a donation and soak up the relics of a bygone era.

Photos of lively residents on the walls belie the reality outside, where a deserted square, abandoned school and derelict houses offer an eerie glimpse into the future of a country at risk of population collapse. 

Lasta is just one of hundreds of depopulated or abandoned "ghost" towns and villages scattered across Greece, in an all too visible marker of years of declining births, economic hardship and mass emigration.

Economists warn that population decline is now putting a major strain on a country just emerging from crisis — with not enough young people to support the economy over coming generations.

"While Greece is seeing very solid growth for the moment, looking ahead, with fewer people to do the work, that's going to be difficult to sustain," Bert Colijn, chief economist at ING, told CNBC by phone.

Falling birth rate an 'existential' threat

Greece is home to one of the lowest fertility rates in Europe: At 1.3, it is half that recorded in 1950 and well below the 2.1 required for population replacement.

Last year, the country recorded just over 71,400 births, the lowest number since records began almost a century ago, and down around 6% on 2022. Greece now has around one birth for every two deaths, and the share of the population aged over 65 is nearly twice that aged 0 to 14.

That prompted Prime Minister Kyriakos Mitsotakis to warn of an "existential" threat to Greek society, with the country more disposed than most to wider demographic shifts afflicting developed nations.

"The truth is that today our people are among the most elderly in Europe," Mitsotakis said last year, speaking at a Greek demographic conference.

It's an issue affecting some pockets of the Greek mainland and its vast archipelago more than others.

"This population decline is not manifested equally throughout the country," Mitsotakis continued. "It has peaks in specific areas and this means that national strategies are not sufficient and local provisions are also needed, with the overall demographic collapse literally becoming an existential bet for our future."

That decline is most visible through the emergence of scores of ghost towns and villages — locations with none or virtually nil inhabitants, deserted as local populations leave or die out. It can be difficult to quantify the exact number of such locations, given their often remote nature, but recent estimates put the figure of entirely abandoned towns and villages close to 200.

Many are all but forgotten, with decrepit buildings the only signs of former life. Others like Lasta, meanwhile, have become sources of offbeat tourism, with visitors to the cafe and abandoned buildings keen to experience a piece of history.

At Greece's last census in 2021, Lasta had a reported permanent population of 12, but when CNBC visited in 2024 there were no signs of permanent residents.

Remnants of the Greek Financial Crisis

Greece's recent demographic decline can be largely traced back to the country's sovereign debt crisis of 2009. Resultant bailout programs sparked years of austerity and financial woe for the country, with the economy contracting by as much as a quarter over the ensuing decade.

Young people were among the hardest hit by the downturn, with youth unemployment peaking at 59.5% in the first quarter of 2013 — more than twice the national high of around 27%.

As a result, many were unable to forge new lives outside of their family homes. Of those who did, many did so overseas, with an estimated more than 400,000 people — or 9% of the workforce — emigrating over the period. Much of the remainder relocated to Greece's big cities, in search of better work and education.

Today, more than half (53.5%) of the Greek population lives in the capital, Athens, and the surrounding Attiki region, as well as the country's second-largest city, Thessaloniki. Meanwhile, all other regions, including Greece's prized islands, have recorded population decline over the past several years.

Many demographers say the country's population decline stems even further back to the 1980s — another period of economic decline. A fall in birth rates over that period has since led to in a reduction in women of childbearing years, with the proportion of women aged 20 to 40 now 150,000 fewer than five years ago.

Initiatives to support population growth

The government is currently forecasting that the population may fall from around 10.4 million today to 7.5 million by 2050 — a decline of more than a quarter.

To help tackle the issue, Mitsotakis last year launched a new Ministry of Social Cohesion and Family Affairs to unify and enhance support for children and vulnerable groups.

In October, the ministry announced that it would spend 20 billion euros ($21 billion) through 2035 on incentives to halt population decline, such as child benefits, enhanced parental leave and tax breaks. Sofia Zacharaki, who heads up the office, said the measures were designed to provide a wake-up call to society.

"We need a shock. We need something that creates, you know, a sense of security and sense of optimism, especially in the younger population," Zacharaki, minister of social cohesion and family affairs, told CNBC via video call.

"We are faced with not just an economic impact ... but also a mindset issue that has been instilled in many young people's minds, probably because of the recurring crisis and probably a sense of disillusionment," she continued, adding that the funding should give more people the choice to start a family.

However, Colijn said he was skeptical that child support measures would be enough to alter the trend, and that major policy changes would likely also be needed to support demographic shifts.

"There doesn't seem to be one example of a policy that's been introduced somewhere that has resulted in a swift turnaround in that decline," he said. He added that other policies might include incentives to encourage more young people to remain in Greece, and attracting back those who left.

Demographic shifts weigh on economic growth

Greece's demographic decline stands at odds with the country's now much improved economic outlook.

The Greek economy is projected to grow 2.2% in 2024, and 2.3% in 2025 — outpacing Europe's major economies. The country's initial 2.9% 2025 gross domestic product (GDP) forecast was revised down only by a wider EU slowdown.

Nevertheless, economists warn that demographic decline could ultimately undermine that growth over the longer term.

"Demographic developments are absolutely key to economic growth in general. It's about how many hands you have to work and how productive those hands can be," Colijn said, highlighting a "strong correlation" between working age population growth and GDP per capita.

Greece is not alone in this phenomena: Demographic decline is an issue facing many developed nations. Japan and South Korea, with fertility rates of 1.2 and 0.72 in 2023, respectively, are among the best known examples of countries in demographic decline. But much of the West, and China too, have rapidly aging populations and need for greater government support.

"We are currently in the midst of an unprecedented demographic transition, whereby global population growth is continuously slowing, with little obvious sign that the trend is about to shift," Jim Reid, Deutsche Bank's global head of macro research, wrote in a November report.

"Given that demographics almost certainly deteriorates further in the 2024-2049 QC [quarter century] it stands to reason that ... you would expect another QC of below long-term average real GDP growth and real equity returns, especially in the DM [developed market] world," he added.