I don't see much reason to believe that any ship built because of the Jones Act would've been built in the US in absence of the Jones Act. So, you really need to show that without the Jones Act that more ships would've been built in the US as opposed to showing that shipbuilding in the US has decreased.
It's like betting on Black for a roulette wheel versus betting on a specific number. You're still going to lose money but you lose the money slower by betting on black than a specific number. You need to show that betting on black loses money faster than a specific number to demonstrate that the Jones Act isn't furthering it's goal.
> I don't see much reason to believe that any ship built because of the Jones Act would've been built in the US in absence of the Jones Act.
No ships were built because of the jones act, that's the problem. The jones act required people to do B if they wanted to do A, so they stopped doing A. A is intercoastal shipping. Nothing in the jones act encouraged B besides the opportunity to do A.
In your roulette example, the example isn't between a specific number and black. It's the jones act is playing roulette versus the non-jones act where you don't. Are you guaranteed to not have lost money by some other means if you never played roulette? No. But roulette is a game that provably loses over the long run, and so we should stop playing it.
Fair enough, I'm not able to evaluate counterfactuals in American maritime law. But on the roulette analogy, I reckon the everything-bagel approach gives you a healthy edge against the house and is well worth betting against.
It's like betting on Black for a roulette wheel versus betting on a specific number. You're still going to lose money but you lose the money slower by betting on black than a specific number. You need to show that betting on black loses money faster than a specific number to demonstrate that the Jones Act isn't furthering it's goal.