Since the majority of the price of a ticket is in the longer-range portions of the flight, regional jets need to be as cost-effective as possible. An aircraft's lifetime cost is a combination of three factors, the purchase price, maintenance costs, and operational costs such as fuel use. If the regional jet's ticket between two smaller airports costs even close to that between two major hubs, the passengers will simply drive instead.
In the early days of the hub-and-spoke model of airline operations in the emmediate post-WWII era, a huge number of war-surplus DC-3's were available at very low costs, so while a number of designs with much better operational costs were available, it wasn't until the mid to late 1950s that airlines were looking for newer aircraft. At this point many of these DC-3's were becoming too expensive too expensive to maintain for passenger use. Many of these were passed on to freight operations while a series of turboprop aircraft took over their market, the Vickers Viscount being one particularily successful example.
This cycle repeated itself in the 1980s when this earlier generation of aircraft was itself becoming too expensive to maintain. deHavilland Canada was in a particularily good position at this point, having just introduced a new aircraft with very low operational costs, the deHavilland DASH-8, which soon took over a good portion of the market. Competition in the form of the ATR-42 and ATR-72 from the Avion de Transport Régional consortium, and the Saab 340 were introduced as well, resulting in the market saturating in a very short time once the earlier designs were replaced. Today only the DASH-8 continues in production, albiet a much larger version.
The latest generation of feederliners are jet designs, a market that was created with the Canadair Regional Jet (CRJ) (CL_600) in the early 1990s and quickly started replacing almost all other designs. The CRJ's range is enough to fill mid-range routes as well, routes previously served by larger aircraft such as the Boeing 737 and DC-9. The aircraft are so inexpensive to operate that they are increasingly being used for direct airport-to-airtport flights, bypassing the whole hub-and-spoke design entirely, and causing a minor revolution in airline operations. The CRJ was quickly joined by the Embraer ERJ and the two designs have since been in competition, with some highly charged political wrangling as a result. A third design from a consortium of Sukhoi, Ilyushin, and Boeing never materialized, and a Fokker-ERNO design ended when Fokker went bankrupt before the design was finallized.
List of regional airliners