Buchi Emecheta's The Slave Girl examines several factors that led one Nigerian woman to enslave another:
Many of the market women had slaves in great number to help them with the fetching and carrying that went with being a full-time trader -- and also in the vain hope that one day the British people at the coast would go and some of these house slaves could be sold abroad just as their fathers and grandfathers had done, so profitably that the abundance of capital and property they had built could still be seen in many families round Onitsha and Bonny and Port Harcourt.[Ch. 5, 53]
Similarly, when describing Ma Palagada, Ojebeta's owner, Emecheta makes the shocking point that some disliked colonial rule in part because it interfered with the revenue earned by "legitimate slave traders":
Without looking at Madam Okeke, Ma Palagada sensed what was going on in her mind and what all these people were thinking. Trade was not as profitable as it used to be during the days of the legitimate slave traders. Now the Niger people had to rely on trading in palm kernels and cloth, mainly cotton from Lancashire in England; and these new types of trade required a great deal of capital investment, rather than just physical strength. [ch 11, 135]
What do the concluding remarks in this passage tell us about the movement from a pre-capitalist to a captialist society experienced by the "Niger people"?
(See also the discussion of slavery and the anti-slavery movement in nineteenth-century Britain in the Victorian Web)