The rare decision to name the hosts of separate Games simultaneously — established with a unanimous vote of I.O.C. members on Tuesday — is an effort by the organization to counter diminished interest shown by democratic nations in hosting the Olympics amid exorbitant costs, white-elephant stadiums, widespread corruption, rampant doping and limited appeal to the youth audience.
Thomas Bach of Germany, president of the I.O.C., has called for an overhaul of the bidding process, saying that too many cities spend millions of dollars as candidates only to go away as losers and become reluctant to bid again. The awarding of two Olympics at the same time would alleviate that concern for the Summer Games for at least the next decade.
The eagerness of Paris and Los Angeles, two of the world’s great cities, to host the Summer Games serves as a welcome rebuttal for the I.O.C. to the embarrassing withdrawals of Boston, Rome, Budapest and Hamburg, Germany, as candidate cities to host the 2024 Olympics. Only Paris and Los Angeles remain in the bidding for those Games.
Paris and Los Angeles are also being viewed as cities that might help reform the Olympics by using mostly existing and temporary facilities to reduce prohibitive costs in staging the Games.
While it is impossible to gauge in advance the voting preferences of delegates of the I.O.C., Paris is considered the 2024 favorite for a number of reasons.
It would be exactly 100 years since it last hosted the Summer Games in 1924. The I.O.C. has also shown a penchant for rewarding cities that continue to bid on the Games after failing to secure them. Since hosting the Summer Olympics in 1900 and 1924, Paris sought without success to host the 1992 Games that went to Barcelona, the 2008 Games held in Beijing and the 2012 Games awarded to London.
The self-regarding I.O.C. also likes to pat itself on the back as a restorative institution and could view the awarding of the 2024 Games as a chance to help Paris continue to recover from recent terrorist attacks.
Paris may also be looked upon more favorably in an international political light at the moment, given that France recently rejected the far-right presidential candidacy of Marine Le Pen while the United States elected the nationalist Donald Trump, who is unpopular in many parts of the world.
By awarding the Games to Los Angeles in 2028 instead of 2024, I.O.C. delegates would guarantee that the Olympics would not come to the United States during Mr. Trump’s presidency.
At the same time, the absence of Mr. Trump from Tuesday’s I.O.C. meeting will become irrelevant if Paris and Los Angeles work out an arrangement on the hosting schedule.
The in-person support of a head of state does not guarantee success, anyway. President Barack Obama’s pitch of Chicago’s bid to win the 2016 Olympics failed when the city finished fourth in balloting to Rio de Janeiro.
Paris will no doubt be cautious to avoid a repeat of its failed attempt to wrest the 2012 Games away from London. That campaign was viewed as smug and arrogant and was surely not helped by remarks from then French President Jacques Chirac, who said, “One cannot trust people whose cuisine is so bad.”
Some experts, however, believe that Los Angeles has a better candidacy and that there is a risk in giving the Games to Paris in 2024, because financial overruns at this precarious moment for the Olympics could continue to scare off future bid cities.
Paris must still build housing for athletes and the news media with a projected cost of $2 billion. Los Angeles, on the other hand, plans to house athletes in existing dorm rooms at U.C.L.A.
Of course, there would also be a potential risk in naming a 2028 Olympic host now, given that no one can know what the political or economic situation will be in either candidate city more than a decade from now.
Los Angeles, which previously held the Olympics in 1932 and 1984, has signaled that it would be willing to host the 2028 Games, even though it prefers 2024. And it seems better prepared than Paris to host at the later date.
In either case, these would be the first Summer Games held in the United States since 1996 in Atlanta. The decision on Tuesday brought relief to the United States Olympic Committee, which was humiliated when Boston, the initial American choice to host the 2024 Games, withdrew its candidacy in 2015 in the face of public disapproval.
The success of the 1984 Los Angeles Games – which turned a $250 million profit – is widely viewed as a sustaining moment for an Olympic movement that struggled after a terror attack at the 1972 Munich Games, financial shortcomings at the 1976 Montreal Games and a United States boycott of the 1980 Moscow Games.
Eric Garcetti, the mayor of Los Angeles, told reporters before Tuesday’s decision that the Olympics “cannot afford to lose the United States,” given its television rights fees and corporate sponsorships that buttress the Games.
“Both of us will find it more and more difficult to convince cities – whether it’s Paris, Los Angeles or other American cities – to really go into this process if one of us gets turned down,” Mayor Garcetti said.