In early January 2011, many North Koreans learned that January 8 was going to be a special day. It was to be marked with numerous events to commemorate the young man who had recently been promoted to the rank of four-star general and made a member of the top executive bodies of North Korea.

The young man's name was Kim Jong-un, and everybody knew him to be the son of the Dear Leader, now dearly departed, Generalissimo Kim Jong Il, even though this family connection had never been explicitly mentioned in the official media.

His birth year was kept secret, although rumour has it that he was born in 1984. It seems that North Korean agitprop shock troopers were embarrassed by the young age of the heir designate. Kim Jong Il's health was deteriorating at the time, but no one expected an immediate succession.

Kim Jong-un's name first appeared in the open-access press in September 2010, but a mere 14 months later, he was made the leader of the entire country after his father's sudden demise in December 2011.

Kim Jong-un is in control in North Korea

At the time, most observers expected that the young Kim would spend the next few years as apprentice to the old guard, his father's senior advisers - who would play the collective role of a council of regency (in all but name).

However, Kim Jong-un is very much his own man. From the first weeks of his rule, he began to break one established pattern after another, showing little interest in the advice of supposed regents.

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What eventually happened to the trio of the top advisers speaks to the situation as a whole. One adviser was arrested in front of cameras at a government meeting and executed the following week, while another, after being invited to an early Sunday morning government meeting, was never heard of again, and yet another is said to be under house arrest (she is the young Kim's aunt, after all).

The strange haircut, eccentric clothing, and penchant for purging top officials ... has made Kim Jong-un the object of ridicule in the world media, but this has led us to overlook some of his achievements...

Kim Jong-un has indeed shown himself to be a tough manager of personnel. Up to 70 top officials - army generals, cabinet ministers, party secretaries and the like - have been executed during his brief tenure.

Among last year's victims, we should not neglect to mention the minister of defence who disappeared in April and is widely believed to have been executed, and a chief negotiator with South Korea who recently died in an ominous sounding "car accident" - North Korea has one motor vehicle per 100 inhabitants.

The strange haircut, eccentric clothing, and penchant for purging top officials and generals has made Kim Jong-un the object of ridicule in the world media, but this has led us to overlook some of his achievements, which are indeed significant.

Even his opponents, the emigre community in South Korea chief among them, generally admit that the young leader is popular with the majority of North Koreans. Purges and executions have only touched the tiny elite in Pyongyang, while for the average person, Kim Jong-un's rule has been a time when living standards have improved dramatically.

North Korean economy is growing

This might all sound surprising to readers of the Western media, but the four years of Kim Jong-un's rule has been marked by significant growth, with the annual growth rate being estimated to be around 3 to 4 percent each year. The previous two decades were a time when the economy fell off a cliff, then stagnated. Things began to get better in the last years of Kim Jong Il, but under his son the improvement speeded up.

Partially, this unheralded success has resulted from changes to the agricultural management. For decades, North Koreans worked for the state, with fixed rations, but Kim Jong-un in 2012 changed the system.

Now farmers work for a share of the harvest, usually some 30 percent. Predictably they work harder, and North Korea's food situation is now better than ever - though only by the standards of East Asia.

Another part of Kim Jong-un's policy has been to overlook the flourishing of the private economy, which is far more powerful than many realise.

In spite of all the Communist rhetoric, nowadays in North Korea one can find not only private restaurants and inns, but also private mines and even oil refineries, not to mention private - and highly profitable - fishing companies. Unlike his father, Kim Jong-un tacitly tolerates private business, and sometimes, quietly encourages it.

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This birthday, Kim Jong-un obviously treated himself with a nice present. On January 6, he conducted a test of what the North Koreans claimed to be a thermonuclear device. This was yet another reminder that the young North Korean leader can afford not to care much about the international community and that he feels as secure internationally as he does domestically.

The young hereditary leader of North Korea who was indeed born in 1984, is going to celebrate his 32nd birthday. This nearly coincides with the fourth anniversary of his reign. His first few years in power have been hectic and turbulent but definitely not disastrous. Nonetheless, it has been a tough ride, and is likely to remain so for a time to come.

Andrei Lankov is a professor of Korean Studies at Kookmin University in Seoul. He is the author of "The Real North Korea: Life and Politics in the Failed Stalinist Utopia".

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.