How many people groups are there? All depends on the counting method.
This method counts a people group for each country it lives in. For example, the Bambara in Mali are considered a distinct people group. If the Bambara live in 12 countries they are counted as 12 people groups. Of the 17,259 people groups by country, 7,220 are considered unreached.
This method counts a people group once regardless of how many countries they live in. For example, if the Bambara live in 12 countries they are counted as only one people group. Of the 10,280 people groups across countries, 4,440 are considered unreached.
Usually called People Groups In Countries (PGIC) and has been the traditional way of counting people groups. This method was used when people group lists were first being developed. Geography i.e. country boundaries were included when defining people groups due to limited communication, expensive travel and minimal migration of peoples.
Usually called People Groups Across Countries (PGAC) and may be the preferred way of counting people groups. Given instant communications, easy travel and dramatic migration of peoples, it seems more relevant today to not consider country boundaries when defining people groups. Note: if a group is in only one country then PGAC = PGIC.
Both People Group In Country (PGIC) and People Group Across Countries (PGAC) views are available. In the title of any profile e.g. "Bambara in Mali" click "Bambara" for a list of Bambara in all countries.