I read a paper that tried to answer why tunnels cost more in New Zealand/Australia/US and Britain. Part of the answer was labor is a much large part of the cost

I read a paper that tried to answer why tunnels cost more in New Zealand/Australia/US and Britain. Part of the answer was labor is a much large part of the cost than one would assume. And second those countries try to push 100% of the risk onto the contractors. One could haplessly think that's free but it's not. Smaller cheaper contractors won't bid[1]. And the largest contractors pad their bids so they will still make money even if everything goes wrong. [1] If you take projects with a 10% chance of bankrupting you, you'll be out of business in no time.