Nigeria
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Nigerains look for employment in other countries.
Army Rebels like Bokoharam
Elections are not Free
Political leaders are very old
Major opposition leaders are over 70 years old.
Not Stable Electricity.
Access to clean water for limited residents.
Proper sanitation for few residents
No Free school at the University
tribalism
no Quality road networks.
no Quality transport system
few Good Infrastructure.
few Good heath care
expensive health care

Botswana
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Namibians do not look for employment in other countries.
No Army rebels
Elections are free
Political leaders are young.
Stable Electricity from South Africa.
Access to clean water for all residents.
Proper sanitation for all urban residents
Building houses to poor people
Paying social grant to pensioners
paying social grant to all children under the age of 18
Free school from tertiary to University
no tribalism
Quality road networks.
Quality transport system
Good Infrastructure.
Good heath care
they use south African currency

Namibia's economy is purely linked to the south African economy. remember Namibia was colonized by South Africa.