Estimation of future steel stock and flow in East Asia

Abstract

A model to estimate future steel stock and demand was developed under the assumption that the steel stock per capita saturates following a sigmoid curve for Japan, China, South Korea and Taiwan. Per capita GDP was used as the variable. Different sigmoid curves were assumed for each end-use, i.e. buildings, infrastructure and automobiles. As in a previous study on automobiles ownership forecast, country-specific saturation values were introduced for steel use in buildings and infrastructure. As an indicator of regional difference, net population density was introduced. The relation between the saturation value and net population density was examined using the Japanese prefectures as samples, and the relation was applied to the East Asian countries. Future population and GDP were substituted into the sigmoid curves and the steel stock and demand was estimated up to 2050. As a result, steel demand for buildings and infrastructure was estimated to reach its peak around 2020 in China, the amount approximately being 330 million tons and 200 million tons respectively. Steel demand for automobiles in China was estimated to continuously increase until 2050 exceeding 100 million tons.