A look at the three contenders for the 2020 Summer Olympics (IOC vote to be held Sept. 7 in Buenos Aires, Argentina):
Population: 13 million.
Previous Olympics: None.
Previous bids: 4 -- 2000, 2004, 2008, 2012.
Bid leader: Hasan Arat.
Number of venues: 38 -- about 70 percent would need to be built; 6 venues would be temporary and dismantled after games.
Organizing committee budget: $2.9 billion.
Infrastructure budget: $19.8 billion.
Public support: 83 percent in Istanbul; 76 percent in rest of Turkey.
Dates: Aug. 7-23.
Slogan: "Bridge Together."
Pros: Vision of bringing Olympics to new region and a predominantly Muslim country for first time; symbolism of holding games in city linking Asia and Europe; "sexiest," most ambitious choice; persistence and commitment shown by fifth bid; strong political support; dynamic bid leader in Hasan Arat.
Cons: June's anti-government protests and police crackdown; doping scandals involving dozens of Turkish athletes; match-fixing scandals in Turkish football; civil war across border in Syria; massive $19.2 billion infrastructure bill for the Olympics; concerns over traffic; seen as another potentially risky choice after games in Sochi and Rio.
IOC evaluation report: "Istanbul 2020 aspires to reposition Turkey and to foster global understanding and inclusiveness by being the first secular Muslim country to host the Games."
Population: 3.3 million.
Previous Olympics: None. Barcelona hosted 1992 Olympics.
Previous bids: 3 -- 1972, 2012, 2016.
Bid leader: Alejandro Blanco.
Number of venues: 35 -- 28 existing and seven to be built.
Organizing committee budget: $3.10 billion.
Infrastructure budget: $1.94 billion.
Public support: 76 percent in Madrid; 81 percent in rest of Spain.
Dates: Aug. 7-23.
Slogan: "Illuminate the Future."
Pros: 80 percent of venues in place; smallest construction budget of 3 bids; compact layout; persistence of three straight bids; experience in hosting major events; influence of IOC executive board member Juan Antonio Samaranch Jr.; popularity of Crown Prince Felipe; momentum picked up from presentation to IOC in June.
Cons: Spain's economic crisis, including double-dip recession and 27 percent unemployment; corruption scandal swirling around Prime Minister Mariano Rajoy; fallout from doping cases and perceived past laxness against doping; potential of some European members voting against Madrid to position another European city for 2024.
IOC evaluation report: "Taking advantage of its existing, modern infrastructure, Madrid 2020 seeks to demonstrate that the Olympic Games can be organized with low financial investment without compromising the delivery of a high quality Olympic experience."
Population: 13 million; greater Tokyo 36 million.
Previous Olympics: 1964.
Previous bids: 2 -- 1960, 2016.
Bid leader: Tsunekazu Takeda.
Number of venues: 36 -- 15 existing; 10 would be temporary and dismantled after games.
Organizing committee budget: $3.42 billion.
Infrastructure budget: $4.38 billion. Tokyo has $4.5 billion "hosting reserve fund" in bank.
Public support: 70 percent in Tokyo, 67 percent in rest of Japan.
Dates: July 24-Aug. 9.
Slogan: "Discover Tomorrow."
Pros: Viewed as safest option with less risks; modern, public transport; legacy from 1964 Olympics; sentimental factor of using Olympics to help Japan recover from 2011 earthquake and tsunami; compact venues and short travel times; $4.5 billion already secured; experience in hosting major events; major Olympic media market; bid leader and IOC member Tsunekazu Takeda and bid CEO Masato Mizuno are popular with IOC members.
Cons: Not seen as a "sexy" choice; Tokyo's trouble explaining "why" Japan needs the Olympics; lowest public approval ratings of the three bids; threat of future earthquakes or tsunamis; leak of radioactive water at Fukushima nuclear plant; Japan's territorial dispute with China over uninhabited islands; potential opposition from some Asian members.
IOC's evaluation report: "Tokyo 2020 seeks to use the power of sport to offer hope to the Japanese people and promote national spirit, unity and confidence, in particular following the March 2011 earthquake and tsunami."
Status: Slight favorite.