Hostile worlds is sociologist Viviana Zelizer's term for the view that the market must be kept separate from intimate, sacred and otherwise important spheres if they are to retain their value and importance. As she says, it is the assumption "that the entry of instrumental means such as monetization and cost accounting into the worlds of caring, friendship, sexuality, and parent-child relations depletes them of their richness, hence that zones of intimacy only thrive if people erect effective barriers around them."