For purposes of the Moody's Analytics estimated and forecast data products, we have established a geography code for the Istanbul metropolitan area in Turkey.

Turkey itself has no official definition for such areas.  Instead, we have utilized the definition published by the Turkish Statistical Institute as part of the Urban Audit study.  The Urban Audit defines the Istanbul metropolitan area, referred to as Larger Urban Zone (LUZ), as the region of Istanbul.  A LUZ is an approximation of the functional urban zone centered around the city.

References:

• Turkish Statistical Institute: Urban Audit Metadata

Table 1 of 1. Turkey's One Metropolitan Area.  We define the metropolitan area as conterminous with a NUTS 2 region of the same name. Turkey has a national geo code of ITUR, all codes for its geographic subdivisions use ITUR as a prefix, and all Moody's Analytics metro areas feature the letter "M."