Why are Bhojpuri, Maithili, and Magahi sometimes included in the Hindi census category?

Bhojpuri, Maithili, and Magahi are often categorized under the Hindi census umbrella due to a combination of historical, educational, and social factors rather than purely linguistic classification.1

• Colonial Classification: During the early period of British rule, these regional languages were grouped with Hindi for administrative and census purposes.1
• Educational Policy: Hindi was designated as the medium of instruction in elementary schools throughout the "Hindi zone," reinforcing its status as the primary language of the region.1
• Social Mobility: Standard Hindi is widely perceived as a language of upward social mobility. Consequently, educated villagers and the urban middle class often identify as Hindi speakers to avoid the stigma associated with using regional languages in public or professional settings.1
• Self-Identification: Many speakers of these regional languages consider themselves to be speaking a dialect of Hindi, and the prevalence of mass media and increased literacy since the 1950s have further solidified the use of standard Hindi.1

While these are often termed "dialects" of Hindi, they are more accurately described as distinct regional languages within the "Hindi belt".1