The manual says: "If you have no projects queued, the number above the hammers
will be in parenthesis."
I have a 26 quality world with mega factories, manufacturing capital, etc, consuming nearly 1/3 of my social output even when there is nothing in the queue. I expected that emptying the social production queue would take the planet's social production out of econ calculations (by using parentheses) in the same way that removing ships takes the planet's military production out of the calculation. This has effectively crippled my economy, since I can't build social projects anywhere else.