The chapter is the last in this section on flexibility, and indeed marks the end of the substantive content of this book. It is linked closely to the rest of the book, and in a sense is the culmination of the scientific agenda pursued thought the book. It provides a link between evidence from the fieldwork of 1994-98 and that of 2001-02 (which involved re-contacting the same subsample of small firms); and a synthesis of the principal themes of the book so far, to wit, dynamics, performance and flexibility. It explains the performance of long-lived small firms in terms of firm-specific turbulence and flexibility (see Chapter 15 for terminology). The evidence presented suggests that (a) a trade-off exists between agility and speed (two measures of flexibility) in responding to external and internal changes; and (b) that firm-specific turbulence has a negative effect on performance. This chapter explores the relationship between firm-specific turbulence, flexibility and performance using data collected in face-to-face interviews with 63 longlived small firms in Scotland. A long-lived small firm is defined as a business that has been trading for more than 10 years. The material below presents information on the database, the variables used in econometric estimation, the key hypotheses and instrument design, before turning finally to the estimates.