Data and replication package for "EU Unwrought Aluminium Imports around the 2026 CBAM Transition: A December Spike and Subsequent Reversal"

Frozen source data, source manifests, legal inputs, code, generated outputs, and audit artefacts for the accompanying study of the December 2025 spike in EU imports of unwrought aluminium under Combined Nomenclature heading 7601, around the start of the definitive EU Carbon Border Adjustment Mechanism regime on 1 January 2026. The package reproduces the focused descriptive analysis through May 2026, the origin-matched EU-US-UK destination comparison on the imports-for-consumption basis, the Stage 1 discovery-screen provenance, the origin-scope and materiality-threshold diagnostics, the official transitional-default audit, and the market-context records, including the archived pre-December EEX EUA futures reference. A single command regenerates every panel, estimate, figure, and table from the raw archived sources under a pinned Python 3.14 environment whose exact dependencies ship with the package; the pipeline verifies the SHA-256 hash of every input before use. The two Comext archives are frozen API vintages. Eurostat does not preserve historical vintages, so a later live query would not reproduce them; they are therefore essential to the deposit rather than a convenience. The official annual Combined Nomenclature distributions are deliberately not included: they are stable published classification releases, and replication/download_cn_annual.py inside the replication package re-fetches them on demand. RIGHTS: this deposit combines materials governed by different source terms and NO BLANKET LICENCE APPLIES. Original code is MIT-licensed (LICENSE_CODE.txt inside focused_replication_package.zip). Eurostat and European Commission material is reused under the Eurostat copyright and reuse notice; US and UK destination records remain subject to their own source terms; the archived European Energy Exchange notice and South32 company announcement remain subject to their publishers' copyright. See RIGHTS.md in this deposit, which governs. Byte counts and SHA-256 hashes for every deposited file are in deposit_manifest.csv.本数据集包含配套研究所需的固化源数据、源清单、合规输入材料、代码、生成结果与审计工件，该研究针对2026年1月1日欧盟碳边境调节机制（EU Carbon Border Adjustment Mechanism，CBAM）正式生效前后，2025年12月欧盟按联合命名法（Combined Nomenclature，CN）税则号列7601进口未锻造铝（unwrought aluminium）的激增情况展开。 本数据包可复现截至2026年5月的聚焦描述性分析、以消费用途进口统计口径开展的匹配原产地欧盟-美国-英国目的地对比分析、第一阶段筛查溯源流程、原产地范围与重要性阈值诊断分析、官方默认过渡审计，以及包含2025年12月前存档的欧洲能源交易所（European Energy Exchange，EEX）欧盟排放配额（EUA）期货参考数据在内的市场背景记录。 仅需单条命令，即可在固定版本的Python 3.14环境中，从原始存档源数据重新生成所有面板图、估计结果、图表与表格；该环境的完整精准依赖项随数据包一同提供，数据流程管线会在使用前验证所有输入文件的SHA-256哈希值。 本存档包内的两个欧盟贸易统计数据库（Comext）存档为冻结的API历史版本。欧盟统计局（Eurostat）不会留存历史API版本，因此后续实时查询无法复现这些数据，故它们为本存档包的必备内容而非可选便利项。官方年度联合命名法（CN）税则分布数据未被刻意纳入：此类数据为稳定发布的分类版本，复现包内的replication/download_cn_annual.py脚本可按需重新获取该类数据。 版权声明：本存档包整合了受不同源条款约束的材料，不适用统一许可协议。原始代码采用MIT许可协议（详见focused_replication_package.zip内的LICENSE_CODE.txt）。欧盟统计局与欧盟委员会的材料可依据欧盟统计局版权与复用声明进行复用；美国与英国的目的地贸易记录仍受其自身源条款约束；存档的欧洲能源交易所公告与South32公司公告仍受其发布方版权约束。本存档包内的RIGHTS.md文件为版权管辖依据。所有存档文件的字节数与SHA-256哈希值详见deposit_manifest.csv。