Prepared by Shahabuddin M. Hossain.
For 1995 and 1996 data, the FOS uses weighted-average exchange rates to derive the naira estimates; beginning 1997, it uses “autonomous foreign exchange market” (AFEM) rate for the purpose.
In addition, as noted earlier, the FOS has, in the absence of actual data, used fixed ratios of value added to gross output to derive value added for the oil sector. Gross output is estimated from the oil production and export price data.
The FOS data do not capture many non-oil exports or non-dutiable imports, particularly for the oil sector. In general, estimates of imports of goods based on central bank exchange transactions data and expressed in U.S. dollars are substantially higher than the customs estimates.
For a description of the consolidation of the fiscal accounts undertaken by the Fund staff, see Chapter IV.
On average, as a share of domestic absorption, staff estimates of aggregate investment are about 10 percent higher than the FOS estimates; staff estimates of aggregate consumption are, as a consequence, about 10 percent lower than the FOS estimates of aggregate consumption.
Once the structure of GDP at current (and constant) prices has been derived, the estimation is a straightforward exercise. The representative exchange rate series can be used to convert naira values into U.S. dollar estimates.