Mismeasuring long-run growth: The bias from spliced national accounts
Leandro Prados de la Escosura 27 September 2014
As demonstrated by the dramatic upward revision of Nigeria’s GDP for 2013, the choice of a benchmark year matters when computing GDP statistics. This column explains how the replacement of benchmark years creates an inconsistency between new and old national accounts series, and how different ways of resolving this inconsistency yield very different estimates of historical GDP levels and growth rates. When used to evaluate the relative historical performance of Spain and France, the interpolation procedure for splicing national accounts produces more plausible results than the conventional ‘retropolation’ approach.
In April it was made public that Nigeria’s GDP figures for 2013 had been revised upwards by 89%, as the base year for its calculation was brought forward from 1990 to 2010 (Financial Times, 7 April 2014). As a result, Nigeria became the largest economy in sub-Saharan Africa. Though spectacular, this is not an exceptional case. Ghana (2010), Argentina (1993), and Italy (1987) also experienced dramatic upward revisions of their GDP. How should this revision affect GDP time series and, consequently, the country’s relative position?
Development Economic history
GDP, GDP measurement, national accounts, statistics, measurement, measurement error, data
China is not yet number one
Jeffrey Frankel 09 May 2014
Many claim that China will soon overtake the US. This column argues that this claim is based on a misuse of statistics. ICP price data is necessary to compare living standards, since a dollar’s worth of yuan buys more in China than a dollar buys in the US. But the fact that rice and clothes are cheap in rural China does not make the Chinese economy larger. What matters for size in the world economy is how much a yuan can buy on world markets. Using the correct prices, the US remains the world’s largest economic power by a substantial margin.
Widespread recent reports have trumpeted: “China to overtake US as top economic power this year.” The claim is basically wrong. The US remains the world’s largest economic power by a substantial margin.
US, China, purchasing power parity, statistics
Gross trade accounting: A transparent method to discover global value chain-related information behind official trade data: Part 2
Zhi Wang, Shang-Jin Wei, Kunfu Zhu 16 April 2014
One common measure of trade linked international production networks is the so-called VAX ratio, i.e. the ratio of value-added exports to gross exports. This column argues that this measure is not well-behaved at the sector, bilateral, or bilateral sector level, and does not capture important features of international production sharing. A new gross trade accounting framework is proposed that can better track countries’ movements up and down global value chains.
competitiveness, globalisation, trade, comparative advantage, global value chains, global supply chain, statistics
Gross trade accounting: A transparent method to discover global value chain-related information behind official trade data: Part 1
Zhi Wang, Shang-Jin Wei, Kunfu Zhu 07 April 2014
The growth of international trade in intermediate inputs means that standard trade statistics can give a misleading picture of the real patterns of production behind world trade. This column introduces an accounting framework that decomposes traditional trade flows into components that better reflect the underlying location of the value addition linked to exports.
Production segmentation across national borders has become an important feature of the world economy. With the rapid increase in intermediate trade flows, trade economists and policymakers have reached a near consensus that official trade statistics based on gross terms are deficient, often hiding the extent of global value chains. There is also widespread recognition among the official international statistics agencies that fragmentation of global production requires a new approach to measure trade, in particular the need to measure trade in value-added.
globalisation, trade, global value chains, global supply chain, statistics