It's an appealing concept: the death of North Korean dictator Kim Jong-il will at last pave the way for the bitterly divided Korean peninsula to reunite after living for six decades with the threat of mutual obliteration.

The catch is that an increasing number of South Koreans, and in particular the younger generation, would it prefer it stayed that way -- just a concept.

I'd much rather not have unification, said Lee Jung-guk, a 21-year old college graduate in Seoul who has yet to find full-time work. If we unify, working people will have to pay more taxes and we need to work harder for economic development.

For a population very aware of its ethnic homogeneity, the years of division have deeply scarred political and social life on either side of what is officially called the Demilitarised Zone but which is in fact bristling with more weaponry than perhaps any other border in the world.

When their 1950-53 war ended, with a cease-fire rather than a peace treaty, both Koreas lay in ruin.

But it was the North, under its founding president Kim Il-sung, which initially looked the better off. The economic comparison is even more stark almost 60 years later, but in reverse.

South Korea's economy is now an estimated 40 times bigger than its neighbour's, it is the world's most wired society and its popular culture enjoys huge success in Asia and beyond.

In contrast, North Korea can barely feed itself, cannot even do simple overseas bank transactions because of tight international sanctions following a series of missile and nuclear tests, and spends huge effort on building up a personality cult to underpin the ruling dynasty that this week passed to Kim Jong-il's son, Kim Jong-un.

For millions of North Koreans, reunification would mean the end of poverty and years of malnutrition. For South Koreans it means at least a decade of slower economic growth.

Estimates on the cost of reunification range to as high as $1 trillion (638 billion pounds) -- South Korea's economic output for an entire year.

A relatively quick and extensive union, like Germany's, would likely be far costlier than a limited integration along the lines of Hong Kong's return to China in 1997 with its one country, two systems approach.

A government initiative for a unification pot with private donations has been largely snubbed by the South's middle class.

The goal is to come up with 55 trillion won (30 billion pounds) to pay for the first year of unification, the government's estimated cost if reunification is done over two decades. The study warned the bill could end up being five times higher.

The fund is just the beginning, said Kwon Mi-ae, a 32-year-old woman who plans to quit her office job to focus on raising her two children.

Unification costs will be astronomical and it will be paid entirely by the people of the South. To be honest, I don't know why we have to pay for all of it, she said.

TIDE TURNS

Kim Jong-il's death has done little to change that view.

Anti-unification ranks swelled last year when deadly attacks blamed on the North -- the shelling of an island close to the sea border and the sinking of a navy vessel -- raised tensions on the peninsula to the highest level in decades.

Opinion polls confirm the changing sentiment as the older generation's longing to reunite is replaced by their children's unwillingness to foot the bill for bailing out a society in the North with which they feel less and less in common.

In a Gallup poll this week, one in four respondents were opposed to unification, the highest level seen in the agency's decade of surveys on the issue. A decade ago, only 7 percent were against unification.

Underscoring the generational divide, an October poll by the Asan Institute for Policy Studies showed that 10 percent of people in their 20s believed unification was unnecessary, compared with 5.5 percent in their 50s.

About a third of the South's 48 million people are under 30.

On the other hand, the view that one Korea should remain the national goal is strong among older South Koreas, especially those who were alive before the 1950s split.

It says in the constitution, doesn't it? said Kim Hong-joon, a 75-year-old retired teacher living in Seoul, asked if unification was anything other than inevitable. I think it should be the ultimate goal of everything the government does.

Both Koreas' constitutions assume they have jurisdiction over the entire peninsula.

FADING HOPE

Dwindling support for unification puts the Seoul government in an awkward position.

The seemingly enormous cost is only temporary, and when you think of it, it's not that large, South Korea's Unification Minister Yu Woo-ik recently told a group of reporters.

It's a level that we are able to afford. Besides, when you look at the cost we're paying for having this division, there you have a much bigger cost and it's cost that keeps accumulating.

The fading hope of any quick unification is perhaps most keenly felt by those who fled the poverty and persecution of the North but left family members behind.

Many fear their loved ones are likely imprisoned back home, possibly subject to torture.

Kim Song-hu, who defected across the Yalu River into China and arrived in the South last year, said the death of Kim Jong-il had not changed anything and that there was no sign the regime was about to collapse and bring forward unification.

I want unification, said Kim, who is 40 and said he left his 11-year-old son and wife behind in the North.

But that's the same for all the defectors who are here now, with or without kids, we want that more than anything else.

(Additional reporting by Iktae Park and Tae-yi Kim; Editing by Raju Gopalakrishnan)