The same bag of rice does not cost the same price. Between Aleg and Kiffa: 59% difference.
01 — The finding
We analysed broken rice prices in 14 markets over the last 12 months. The cheapest: Aleg, 247 km from Nouakchott, at 36.7 MRU/kg. The most expensive: Kiffa, 512 km on the same road, at 58.3 MRU/kg.
The spread is 59%. For a family of six consuming 150 kg of rice per year, this represents an annual extra cost of 3,240 MRU in Kiffa compared to Aleg.
14 markets, average of last 12 months. Bars are coloured by supply corridor.
02 — Distance
One might think the farther from the port, the higher the price. We tested this hypothesis with linear regression on markets along the Road of Hope.
The result: R² = 0.004. Distance explains 0.4% of price variation. The slope coefficient is +0.15 MRU per 100 km, with a p-value of p = 0.91. Statistically: no relationship.
Aleg is at −10.8 MRU from the prediction. Kiffa is at +10.5 MRU. Néma, at 940 km, is almost on the prediction line. Something other than distance determines the price.
Broken rice price vs distance from Nouakchott. Road of Hope only.
03 — Minimum wage
The minimum wage rose from 3,000 MRU to 4,500 MRU in January 2023. It had been frozen for twelve years. During that time, rice prices increased.
In Aleg, a family on minimum wage spends the equivalent of 16.3% of annual salary on rice. In Kiffa: 26%. That's 1.2 months of extra salary per year for the same product.
Share of annual minimum wage spent on rice, by market. Family of 6, 150 kg/year.
04 — Other products
Spreads exist for vegetable oil and wheat too. But the cheapest corridors are not the same.
For oil, the southern border wins: 65.9 MRU/L in Maghama, against 92.8 MRU/L in Atar on the Road of Hope. A spread of 41%.
For wheat grain, it's Aleg again: 15.0 MRU/kg, against 24.2 MRU/kg in Atar. A spread of 62%.
The cheapest market is not always the one we think. It's not the closest to the port. It's not the farthest either.
Why is Aleg cheaper than Nouakchott? Why does distance not explain prices? The AI knows all 23 markets, all correlations, all surprises.