1. SAGE at the University of Wisconsin–Madison; Centre for
Sustainability Studies in Veracruz, Mexico; Global Footprint Network, 3270
Lakeshore Avenue, Oakland, CA 94610-2720, USA; tel: +1 510 839 8879
2. Global Footprint Network, 3270 Lakeshore Avenue, Oakland, CA 94610-2720,
USA; tel: +1 510 839 8879