BEIJING - China will revise historical regional GDP data under a unified accounting mechanism to be introduced early next year, the National Bureau of Statistics said Friday.

The new mechanism will unify the standards and procedures for calculating national and local GDP numbers, which had been calculated under different accounting methods adopted by local and national statistics authorities since 1985, the bureau said in an online statement.

The reform is expected to close the current discrepancy between national and regional figures, improving data quality while enhancing the credibility of government statistics, it said.

To ensure data comparability, the country will also revise historical local GDP figures and publish them in 2020, the bureau said. The revised figures for 2018 will be released together with the 2019 numbers.

As the economic activities of some government institutions are only reflected in the national GDP, the combined regional number will be slightly lower than the national amount.