Beware of recession-induced "threat-rigidity effects," strategy professor Freek Vermeulen warns. Firms in hard times "are inclined to more narrowly and firmly focus on the one thing they do well (e.g. their core product or service), stop doing other things, and become more hierarchical and top-down in terms of management control," he says. Bad move, he writes. His advice? Try to open up by "exploring new sources of potential revenue and experimenting with bottom-up processes to generate such ideas and innovations."