# GSP(I/E) Measure

21.145 The GSP(I/E) is a derived income and expenditure measure used to overcome the inability to derive all components of the GSP(E) measure. This approach relies on the assumption that GSP(E) is equal to GSP(I).

21.146 The compilation of the GSP(I/E) measure involves a number of steps:

- Derive current price GSP(I);
- Assume GSP(I) equals GSP(E), and obtain current price GSP(I/E);
- Aggregate known components of GSP(E) (i.e. state final demand and international trade), for current price and volume estimates;
- Calculate adjustments to known components of GSP(I/E) for current price and volume estimates. These are largely modelled estimates which are added to ensure price deflators more accurately reflect state economies;
- Calculate volume and current price aggregates for adjusted known components of GSP(E). This involves adding adjustment calculated as part of step 4 to aggregate known components of GSP(E) in Step 3;
- Produce an implicit price deflator (IPD) using adjusted known components of GSP(E) created as part of Step 5;
- Apply the IPD (from Step 6) to the current price GSP(I/E) to derive GSP(I/E) in volume terms; and
- Create balancing item as a residual of GSP(I/E) and known components of GSP(E) for current price and volume components.

## GSP(I/E) Current price

21.147 Current price GSP(I/E) is produced by assuming GSP(I) is equal to GSP(E) (which cannot currently be measured entirely using available data sources). This relies on the national accounts where for balanced supply-use years GDP(I) is equal to GDP(E). GSP(I) is then used to allocate GDP to states to produce current price GSP(I/E).

21.148 GSP(I/E) is benchmarked to the average of current price GDP(I) and GDP(E) for the current year and pre-supply-use years, wherein GDP(I) is not equal to GDP(E); that is:

- create Australia-level GDP(I/E):

\(\large GDP(I⁄E)= \frac{GDP(E)+GDP(I)}{2}\)

- benchmark the state income measure to the above GDP(I/E) measure:

\(\large GSP(I⁄E)= \frac{GSP(I)}{GDP(I)} ×GDP(I⁄E)\)