The claim uses compound interest calculations to quantify the financial debt created by slavery. The methodology typically begins with an estimate of the total value of enslaved labour, calculated by multiplying the number of enslaved people by their working hours and a market wage rate for the period. This principal sum is then compounded at a chosen interest rate from the date of emancipation (or sometimes from the start of the slave trade) to the present day. The resulting figures are very large, ranging from several trillion to tens of trillions of pounds depending on the assumptions used.
Advocates use these calculations to demonstrate that the moral and financial scale of the debt is far larger than any political discussion has acknowledged. The argument is that if a comparable debt had been created by any other means, such as unpaid commercial loans, it would be legally enforceable regardless of how much time had passed. The passage of time does not extinguish the debt; it increases it. Britain, the argument goes, owes a sum so large that even significant reparations payments would represent only a fraction of the true liability.
The Barbados government, following calculations produced by CARICOM-linked academics, has cited a figure of $4.9 trillion as Britain’s obligation to Barbados alone. Other calculations suggest the total global liability runs to over £200 trillion.
