Expanded S-Curve Model of a Relationship Between Crude Steel Consumption and Economic Development: Empiricism from Case Studies of Developed Economies

Different economic development stages are associated with distinctive patterns of steel consumption, and the forecast of future steel consumption has been an intriguing subject. This article takes a pragmatic approach to the examination of intrinsic relations between crude steel consumption and economic development using historical data of the past 100 years from 11 developed economies. The relations between crude steel consumption and GDP can be described by an expanded S-curve model: with the growth in GDP per capita and per capita steel consumption showing an expanded S-curve of “slow growth–rapid growth–zero growth, or even negative growth.” The patterns of crude steel consumption in different economic development stages are characterized by different transitional thresholds, which are referred to as the takeoff point, turning point, and zero-growth point of the per capita crude steel consumption. Using a mathematical model and the critical thresholds, the expanded S-curve can be divided into four transitional sections: slow growth, accelerated growth, decelerated growth, and zero/negative growth. The expanded S-curve model is expected to be a foundation for forecasting crude steel demand in different economies or in the same economy at different economic development stages.