[pavlov]

The Olkiluoto 3 nuclear power plant in Finland. It’s a new type of reactor and one of the only nuclear projects in the West.

Construction started in 2005 and the plant was supposed to be online in 2010. Eleven years later it’s still not operational.

Original budget was 3 billion euros. Current estimate is over 11 billion.

[liketochill]

Wise moves on the part of the project proponent, had they presented their project with a 17 year construction and 11 billion euro budget it never would have been started.

Humans are optimistic. If we knew in the beginning how long something will actually take we never would start many things.

[rocmcd]

This is the "hiding hand" principle at play.

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

I highly recommend anyone interested in "megaprojects" to listen to this EconTalk podcast episode with Bent Flyvbjerg:

https://www.econtalk.org/bent-flyvbjerg-on-megaprojects/

Very insightful conversation.