1. NATIONAL STATISTICAL INSTITUTE
Introduction of the annual overlap method to the compilation of Bulgarian quarterly national accounts
TF-SAQNA
15 February 2007

2. NATIONAL STATISTICAL INSTITUTE
CURRENT STATE
Currently produced and published quarterly volume series are:
in prices of the correspondent quarter of the previous year
in prices of applying over-the-year method
Since over-the-year technique is only suitable for measuring 4-quarter growth and continuity in growth rates is not satisfactory, the annual overlap method was considered as more reliable.
TF-SAQNA
15 February 2007

3. NATIONAL STATISTICAL INSTITUTE
NEW METHOD FOR LINKING
А few considerations were taken into account when making the decision to use this method:
quarterly growth rates average to years, so quarterly and annual levels keep in step (temporal additivity);
the method eliminate the risk of the so-called drift problem.
In order to review the method interim chain-linked estimates are calculated.
TF-SAQNA
15 February 2007

4. THE EFFECTS OF APPLYING THE CHAIN-LINKING
NATIONAL STATISTICAL INSTITUTE
NATIONAL STATISTICAL INSTITUTE
THE EFFECTS OF APPLYING THE CHAIN-LINKING
The effects of applying the annual overlap method can be found by looking at the difference between this method and the over-the-year method in GDP growth.
TF-SAQNA
15 February 2007

5. NATIONAL STATISTICAL INSTITUTE
SEASONAL ADJUSTMENTS
Because of the very initial state of the annual overlap method in Bulgarian QNA, over-the-year technique is still used in seasonal adjustments.
TF-SAQNA
15 February 2007