Based upon current actuarial tables:

https://www.ssa.gov/oact/STATS/table4c6.html

If someone is around 20 years old, they will on average be expected to live around another 60 years, to age 80, meaning the year 2080 today.

If someone who is 10 years old today joins in another 10 years after this market starting, they will live to the year 2090 on average (putting them at 80, with a stretch goal at 100 in the year 2110 with extremely low likelihood).

(added 20230714: the above actuarial table is just an example, there may be many).

However:

1) People are usually overconfident and think they are going to live beyond the average. Few actively expect themselves to be the sad sap that dies early if they don't have a good reason to. So someone might reckon that they will live to 100 years old, which would put a 20-year old player at around the year 2100, and they might join the market thinking, "yeah, I'm super healthy, I will make it to 2100." If they don't join, they are tacitly agreeing that they will probably not make it to 2100, questioning their own mortality.

2) Use this same logic for someone who is 10 years old today, who will be about 20 years old in 10 years from now, when they join the market. Will they join and reckon that they are super healthy and vote YES?

3) Or, will people be logical and look at the actuarial tables, will there be a sufficient number of individuals who see others logically, even if they don't look at themselves logically, and think, "No, they clearly are not likely to make it that long, just look at the tables."

Basically this is a market testing people's level of denial of their own liklihood of death at an average age, essentially it's a death dunning-kruger market.

From @jack , I agree with this statement:

I assume there's an implicit deadline of 2033 by which the participant must have joined, otherwise someone could just join in 2100 and then live ten more years and then it resolves YES. Please state this explicitly.

• 20230714: Info regarding actuarial tables is contextual only. There is no one set of definitive actuarial tables that lasts forever.

• 20230714: For the purposes of this market, 18 years old at the time of counting is the cutoff for participating for no reason other than I am not comfortable with doing anything close to encouraging kids gambling.