Prior studies investigate the relationship between top-management
commitment and collaboration with suppliers. Nevertheless, the
relationship between environmental activities and green supply chain
has not been discussed. This study finds that top-management
commitment also positively and significantly impacts environmental
collaboration with suppliers, and demonstrates that top-management
commitment positively and significantly influences buying firm
adoption of green purchasing. Therefore, green purchasing could be
motivated directly by top-management commitment and indirectly by
top-management commitment via environmental collaboration with
suppliers. If top-management fails to proactively lead in environmental
cooperation and vertical integration with suppliers, its influence on
green purchasing reduces.