The South Korean central bank, the Bank of Korea, publishes an annual summary of the DPRK’s economic performance the previous year. The 2013 report is out. You can also download it on my DPRK Economic Statistics Page.
Here is a summary in Yonhap:
The Bank of Korea (BOK) estimated that the country’s economy expanded 1.1 percent in 2013, slowing from a 1.3 percent on-year expansion in the previous year.
In 2012, the North Korean economy was estimated to have grown at the fastest pace in four years, after contracting 0.9 percent and 0.5 percent in 2009 and 2010, respectively.
A BOK official explained that while the North’s construction sector shrank last year, its agricultural output improved on favorable weather conditions.
An expansion in production of coal and iron ore also lent support to growth, the official added.
Pyongyang’s construction industry contracted 1 percent on-year, compared with a 1.6 percent decline in 2012, as an increase in the number of residential buildings failed to offset falling demand for road construction works.
Its agricultural and fishery industry, which accounts for 22.4 percent of its total output, expanded 1.9 percent last year, slowing from a 3.9 percent growth in 2012.
Growth in its mining and manufacturing industries, which account for 35.7 percent of overall output, gained traction to reach 1.5 percent, up from 1.3 percent a year earlier.
The data, meanwhile, showed that North Korea’s nominal gross national income (GNI) came in at 33.8 trillion won (US$33.3 billion) last year, which is roughly 2.3 percent of South Korea’s 2013 GNI of 1,441.1 trillion won.
The Wall Street Journal’s Korea Real Time notes the following:
“North Korea has neither the capability to collect and analyze all the relevant data necessary to measure its own GDP growth nor the willingness to disclose them to the outside world,” says Mr. Cho.
Marcus Noland published a graph of korean growth rates from 1990-2013 and offered comments on the BOK’s methodology:
And Noland’s comments:
According to the report, BOK constructs its national income account estimates “using basic data on North Korea’s economic activities supplied by relevant institutions…GDP at current prices is estimated with the use of South Korean prices and value-added ratios.”
What this means in non-economist speak is that someone (the NIS?) gathers data using some sources and methods which presumably put an emphasis on physical indicators that are easily countable. So that, as a practical matter, the South Korean authorities may have a better grasp of output in some sectors (like coal, where it’s easy to count railcars leaving a limited number of mines) and less on say services such as education where both the quantity and quality are more difficult to observe. Not surprisingly, the agricultural and industrial sectors of the economy show more output variability than does services. Whether this reflects reality or just problems counting physical indicators for services is unknown.
Then, having obtained these physical measures of output, we need prices and value-added weights to aggregate them into a single measure of the value of output. According to the BOK report they use South Korean prices and value-added weights. There are two problems here, though one problem may be diminishing over time. The first problem is that the relative price structures of the North and South Korea economies are not the same. However, over time it appears that the structure of domestic prices in both economies is getting more like world prices, and hence more like each other. So differing relative prices is probably less of an issue today than say 20 years ago.
Its less clear that the problem is disappearing with respect to the use of South Korean value-added weights that reflect the underlying techniques of production which remain vastly different across the two economies. Bottom line: we know there are some non-trivial problems with using the South Korean data to construct the North Korean GDP estimates.
Rumors have long circulated that the South Koreans either obtained or constructed a North Korean input-output table which they could use for these calculations, and contrary to the statement in the BOK report, weights derived from this source are used to construct the North Korean national income estimates, not the South Korean value-added weights. I personally do not know whether these claims are true or not.