What are the tax breaks and tax write off like in the US?

Depending on the location, they can be pretty darn generous and advantageous for the production studios. Two good examples that come to mind would be Louisiana and Georgia - both states offer generous tax breaks to production studios that film in those states, under the guise of "bringing in business". That said, with Georgia and Florida both standing up for themselves and no longer allowing Hollywood studios to swing their dicks around regarding state politics, it'll be interesting to see how the studios respond.*

*I still give the Hollywood film industry a decade at best to live. They were already on fire and now going into freefall.