The effects of term limits on the political system have been widely studied, although most research on this topic focuses on legislative rather than executive behaviour. Some empirical research on term limits points out their negative effects. However, it is inconclusive, as evidence supporting both positions has been found. The seminal study of John M. Carey shows that term limits do not improve policies, nor do they eliminate the impact of private interests on legislative behaviour. Another study shows that legislators who can no longer seek re-election sponsor fewer bills, are less productive on committees, and are absent from more floor votes. Term- limited politicians dedicate less effort to their office, engage in opportunistic behaviour, and frequently run for another office or for a different party. Recently, a 2017 study of the effects of term limits on representation in US state legislatures provided no evidence that term limits improve collective representation. Moreover, term-limited officials pay less attention to local matters, focusing instead on nationwide issues.