We analyse the take-up by firms of internationally recognized standards such as ISO 9000 and ISO 14000. Based on an analysis of 11,668 firms in countries in Asia and Eastern Europe, we conclude that the probability of standard certification increases with firm size, is greatest in large cities and in manufacturing industries. There are other differences, including between countries. Given these differences, we argue that single generic standards for all firms may not be optimal and that there is a case for the simultaneous publication of differentiated standards targeted at different user characteristics.