The average fraction of disposable income spent on food, beverages, and tobacco ranges from 17% in high-income countries to 53% in low-income countries. Americans typically devote less than 10% of their budget for this purpose, whereas the average Nigerian may have to spend 73% of his disposable income.
Since 2001 the University of Michigan’s Center for Sustainable Systems has developed a growing set of factsheets that cover topics including energy, water, food, waste, buildings, materials, and transportation systems. Each factsheet presents important patterns of use, life cycle impacts and sustainable solutions. They are designed to inform policymakers, business professionals, students and teachers. The factsheets are peer-reviewed and updated annually.
Sustainability Indicators
 U.S Environmental Footprint |
 Biodiversity |
 Social Development |
 Carbon Footprint |
Energy
 U.S. Energy System |
 U.S. Renewable Energy |
 Wind Energy |
 Photovoltaic Energy |
 Biofuels |  Nuclear Energy |  Geothermal Energy |
Material Resources
 U.S. Material Use |
 U.S. Municipal Solid Waste |
Food
 U.S. Food System |
Water
 U.S. Water Supply |
 U.S. Wastewater Treatment |
Built Environment
 Green IT |
 U.S. Cities |
 Residential Buildings |
 Commercial Buildings |
Mobility
 Personal Transportation |
Climate Change
 Greenhouse Gas |
 Climate Change Science and Impacts |
 Climate Change Policy and Mitigation |