SEOUL - Almost every night, seeking to gather opinion from a country where opinion is often punishable, Kim Eun Ho calls North Korea. He talks mostly to people in Hoeryong city in Hamgyong-bukto province, and the conversations never last long. Hoeryong city employs 14 men who monitor the region's phone conversations, Kim believes, and typically they can tap a call within two or three minutes. Kim says he knows this because, as a North Korean police officer before he defected in December 2008, he sometimes monitored the conversations.

But these days, with Pyongyang preparing for a Workers' Party convention that could trumpet the rise of leader Kim Jong Il's youngest son, Kim Eun Ho and other defectors who speak regularly to North Koreans hear plenty of opinions reflecting what he described as a broad sentiment against hereditary succession.

"Of 10 people I talk to," he said, "all 10 have a problem with Kim Jong Eun taking over."

Just as North Koreans know little about their potential future leader, the rest of the world knows almost nothing about North Korean opinions. Recent academic research, based on surveys with defectors, suggests that North Koreans are growing frustrated with a government that allowed widespread starvation in the early 1990s and orchestrated brutal currency reform in 2009 that was designed to wipe out the private markets that enable most residents to feed themselves.

The defectors are motivated to emphasize the worst-case scenario in their homeland. There are some who think that Kim Jong Eun will take power and gradually lead North Korea to Soviet-style reforms. Some defectors say that even though the younger Kim is largely unknown, they hope he'll allow for a free economy after his father dies.

Still, in South Korea, an emerging patchwork of mini-samples suggests that many North Koreans view their government as a failed anachronism, and they see the young general, as he's called, as a sign of the status quo. They associate Kim Jong Eun with the December 2009 currency revaluation. They don't know his age - he's thought to be in his late 20s - but they think he's too young to be anything more than a figurehead.

Sohn Kwang Joo, chief editor of the Daily NK, a Seoul-based publication focusing on North Korea, receives frequent reports from stringers in four North Korean provinces. Those ground-level reporters, gathering information mostly from intellectuals, farmers and laborers, suggest to Sohn that "eight or nine out of every 10 people are critical of Kim Jong Eun."

A recent report from PSCORE, a Seoul-based nongovernmental organization promoting harmony on the Korean Peninsula, suggested that two party officials were sent to a gulag last month for slandering the chosen heir. Kim Young Il, a PSCORE director who was in China during Kim Jong Il's recent trip, said: "Criticism of Kim Jong Eun is very strong. . . . What you see now is face-level loyalty, but it's not genuine."

Kim Eun Ho, the former North Korean police officer, works as a reporter for Seoul-based Free North Korea Radio. The nightly routine testifies to the difficulty of gathering information from within the world's most reclusive state.

Kim first calls a friend who lives close to the Chinese border, where a smuggled foreign cellphone receives a clear signal. When Kim reaches his friend, the friend uses a second phone - a North Korean line - to call one of Kim's police sources in Pyongyang.

The friend then places the North Korean phone and the Chinese phone side-by-side, volume raised on the receivers, allowing Kim an indirect, muffled connection.

For extra caution, the conversations rely on code words.