The greater than 100% anomaly in Lagos is plausible for a number of reasons. Firstly, the value of the denominator, which is the estimated adult population in Lagos, represents where people live, rather than where they work–in other words, the night-time population. The day-time population is likely to be much higher than at night, since Lagos is a business hub that receives residents from neighbouring states during the day. The BVN database captures information on the location where the account was opened, not where the individual resides. Additionally, a BVN is assigned to an individual for life. Therefore, if an individual opens an account in a location of high-penetration and moves to a low-penetration area, the BVN location information doesn’t change. Finally, the GRID3 population dataset that was used does not provide estimates in designated commercial areas, which comprise a large part of Lagos. These factors contribute to an overestimation of financial inclusion in Lagos, particularly because it is a state with so much commercial activity.
In addition to this index, which captures the entire population, gender-specific calculations were generated. The “unbanked” male and female populations were calculated by simply subtracting the number of BVN accounts by the total male and female populations at national and regional scales. 61% of the total population is unbanked.