I'm experimenting with using Manifold for more long-term prediction formats and am curious to hear about your thoughts on this.

You may have heard that they are currently building a tunnel under the Fehmarn Belt, to connect Germany and Denmark. You can learn more about it here:

https://en.wikipedia.org/wiki/Fehmarn_Belt_fixed_link

https://femern.com/the-tunnel/fehmarnbelt-tunnel/

The project website linked above claims that the tunnel will open in 2029. But will it? This can obviously resolved by the end of 2029.

If delays to the project are announced that put the expected completion to 2030 or later, this market will immediately resolve No. This distinguishes it from this related market:

https://manifold.markets/Kurgan/will-the-fehmarn-belt-fixed-link-be

Large construction projects frequently suffer from delays, so a No resolution seems quite likely to me. This is an interesting mechanism for dealing with the long-term markets that normally bind capital for very long periods - this market might resolve tomorrow if they announce the delay so soon.

Note that this market only concerns the Fehmarn Belt tunnel discussed in the links above. Its effective use depends on a second, much smaller tunnel under the Fehmarn Sound, to connect the german island of Fehmarn to the german mainland. The small tunnel and any other supporting infrastructure is irrelevant to this question.

Note that this market mainly concerns the expected completion date rather than the actual completion. If a delay is announced tomorrow, the market will resolve No. They may be able to speed up and actually still finish the project in time, but the market will already be resolved at that point.