Is America dematerializing? Trends and tradeoffs in historic demand for one hundred commodities in the United States

We introduce a broad yet detailed data framework to assess the physical basis of modern industrial societies based on trends in their commodity demand. Using the example of the United States from 1900 to 2020, we consider both absolute commodity demand (ABS) and demand indexed to economic activity, otherwise known as intensity of use (IOU), for one hundred commodities that constitute the bulk of the material entering the US economy annually. The commodities selected are generally raw materials that enter the economy as industrial inputs that are further processed and incorporated into intermediate and finished products. The data show that ABS for nearly all the 100 commodities rose steadily until 1970 with IOU consistently rising for many as well. After that time, the trends for different groups of commodities start to diverge. Comparing ABS and IOU for the years 1970 and 2020 brings into focus the divergent trends. We find that for many metals and mineral commodities, domestic consumption fell over the last half century, though much of this missing consumption may represent production displaced to other locations. For a larger cross section of commodities, consumption grew but more slowly than the rest of the economy, as per capita consumption for many basic industrial and consumer commodities remained roughly steady. For a small group of commodities, including technology metals, consumption grew faster than the rest of the economy between 1970 and 2020. By examining a large range of commodities over time, we develop a disaggregated framework for more rigorously assessing whether contemporary industrial societies are dematerializing, that is, reducing the amount of physical material necessary for their economies to function. Though restricted to the United States, this study has relevance to other countries around the world in elucidating the underlying physical basis of modern economies with implications for environmental quality, economic competitiveness, and national security.

Methods
The database is an Excel workbook with three tabs. 

Tab 1 - Table S1 (Historical Data)  - Contains the reported data on apparent consumption of 100 commodities in the United States generally denominated in metric tons.  These data were not generated, or calculated, but taken directly from were collected online from US government natural resources agencies.  No processing of the data took place other than normalization.  Table S1 also includes a times series from 1900 to 2020 on US Gross Domestic Product. 

Tab 2  - Table S2 (Technical notes) - Gives the source of data for each of the commodities listed in Table S1 as well as technical notes regarding the data as necessary.

Tab 3 - ABS-IOU – Presents the calculated values for the variables IOU2020/1970 and ASB2020/1970 as shown in Figure 3 of the paper.  These calculated values are based directly on data from Table S1.

本研究提出了一套兼具广度与精度的数据框架，用于基于大宗商品需求趋势评估现代工业社会的物质基础。本研究以1900年至2020年的美国为案例，针对每年进入美国经济体系的核心大宗商品（共100种），同时考量绝对大宗商品需求（absolute commodity demand, ABS）以及以经济活动为基准的需求指标——即使用强度（intensity of use, IOU）。本次选取的大宗商品多为以工业原料形式进入经济体系，并经进一步加工转化为中间品与最终产品的原材料。

数据显示，截至1970年，几乎所有100种大宗商品的ABS均呈稳步增长态势，其中多数的IOU也持续攀升。在此之后，不同类别大宗商品的趋势开始出现分化。对比1970年与2020年的ABS与IOU指标，可清晰展现这种分化趋势。研究发现，在过去半个世纪中，多数金属与矿产大宗商品的国内消费量有所下滑，而此类消费缺口很大程度上源于生产环节向海外转移。对于更多种类的大宗商品而言，消费量虽有所增长，但增速低于整体经济增速，这是因为多数基础工业与消费品大宗商品的人均消费量基本保持稳定。而包括科技金属在内的少数大宗商品，其消费量在1970年至2020年间的增速高于整体经济增速。

通过对多类大宗商品的长期追踪分析，本研究构建了一个细分维度的分析框架，可更严谨地评估现代工业社会是否正在发生物质脱钩（即降低经济运行所需的实体物质投入）。尽管本研究仅聚焦美国，但对于阐明现代经济的内在物质基础具有普适性参考价值，其结论对环境质量、经济竞争力与国家安全均有借鉴意义。

## 研究方法
本数据集为包含三个工作表的Excel工作簿：
1. 工作表1：表S1（历史数据集）——包含美国100种大宗商品的表观消费量数据，单位通常为公吨。此类数据并非自主生成或计算，而是直接取自美国政府自然资源管理机构的公开在线数据集，仅经过标准化处理，未进行其他加工。表S1同时涵盖了1900年至2020年的美国国内生产总值（Gross Domestic Product, GDP）时间序列数据。
2. 工作表2：表S2（技术说明）——列明了表S1中所有大宗商品的数据来源，并根据需要附带有数据相关的技术说明。
3. 工作表3：ABS-IOU——展示了本研究论文图3中提及的IOU2020/1970与ABS2020/1970变量的计算值，此类计算值直接基于表S1中的原始数据生成。