证据缺口：我们尚不知道什么，以及将如何解决

11.1 The most important gaps

Four gaps matter most for the size of the market and the iron-unit balance.

The first is the absence of an official apparent-steel-use series. The starting point of 450 kt is an industry estimate reported in October 2026 [S01]. It is consistent with 2022 to 2023 production and trade data, but a bottom-up check on 2025 data gives roughly 410 to 570 kt, and the ratio of cement to steel use, 10 to 15 times against about 2.2 worldwide, suggests that steel use may be understated or cement demand overstated (Chapters 3 and 7). A national steel balance, built annually from production, imports and exports by product, would replace it with a measured value. Such a balance requires plant-level production data, which producers do not publish.

The second is the age of the product-level trade data. Cameroon’s detailed import data in UN Comtrade stop in 2023, while the national statistics institute’s 2025 data, which show a 33% rise in chapter 72 tonnage, are available only at chapter level [S05][S07]. The product composition of the 2025 increase, in particular whether it was driven by billets, is therefore unknown.

The third is domestic scrap. The only quantified study of scrap arising dates from 2006 and found 53 to 62 kt a year [S27]. The 40% scrap share reported by industry gives an implied volume of about 108 kt in 2023, but no direct measurement exists, and no legal text on scrap exports was found [S20][S123].

The fourth is the population base. The provisional census count of 22.7 million is about 24% below the estimates of international institutions [S15]. Tonnage-based estimates do not change, but per-capita indicators and the growth path of the population do.

11.2 Register of evidence gaps

Table 11.1 derivedEvidence gaps, their effect on the analysis and the plan to resolve them

Source: Cameroon Steel. Expected dates are targets, not commitments.

11.3 Items that could not be verified and are not used

Some figures in circulation could not be verified and are not used as facts in this paper. A press report of 1.107 Mt of reinforcing-bar production in Gabon in 2024 is implausible against Gabonese imports of about 51 kt and is excluded [S30]. Tonnage estimates of steel demand for the other CEMAC states could not be built from trade data and are replaced by the value-based envelope of Chapters 6 and 7, which is labelled as indicative. Capacity figures for individual Cameroonian plants are quoted as reported by each source and are not added together.

Industry-wide figures reported in the press, such as installed transformation capacity of about 1.2 Mt and utilisation of about 50%, are used with attribution and treated as indicative because their definitions are not published [S20][S01]. The figure of "627 tonnes" for rebar capacity published in May 2026 is read as 627 thousand tonnes, consistent with earlier statements of 260 kt and 450 kt [S03][S56][S80].

11.4 How later editions will improve the evidence

Cameroon Steel intends to update this paper as new data become available, and in particular to publish, with partners, an annual steel balance for Cameroon covering production, imports, exports and apparent use by product. A transparent balance would serve producers, importers, policymakers and lenders alike, and would allow the scenarios of Chapter 7 to be tested against outcomes. The data behind every chart in this paper are published with the web edition so that others can check, reuse and challenge them.