Constituency Service and Incumbency Advantage

Numerous scholars have documented a dramatic increase in incumbency advantage in US congressional elections and also state legislative elections over the past four decades.' For example, Gelman and King show that incumbents in the House of Representatives now receive about twelve extra percentage points solely as a result of holding congressional office during the campaign;' the comparable figure for most of the first half of this century was only 2 per cent. This advantage of incun~bency has made members of the US House and many state legislators nearly invulnerable to electoral defeat. Many agree that incumbents' use of constituency service explains their widening lead over challengers. The perquisites of legislative office include the franking privilege, money for travel to the constituency, staff support and other benefits that enable members of congress to provide many services to, and answer many specific requests of,