Why must you people always be so black and white? Of course material was produced before copyright, and would continue to be produced if copyright were replaced or abolished. That is not in dispute. The question is whether copyright is an effective promoter of the production and distribution of works. Does it mean more works get to people? Are those works of higher quality? Does any given work reach more people who enjoy or benefit from it (there is more than enough creative work in the world to last many lifetimes, so getting the right works to the right people is a useful goal)? You used the word "promote" yourself, yet you crudely attempt to gloss over these issues by trying to reduce the debate to a single, mundane question: would [any] material still be made without copyright?
And what is with your obsession with funding from the public purse? Copyright is not a purely macroeconomic tool. A very important part of the system is that it creates a direct channel for reward between consumer and producer: those who distribute their works to more people or are more valuable have more opportunity to benefit, thus there is a direct incentive to increase quality and maximise distribution.
Of course, old-fashioned set-ups where big organisations take the copyright in exchange for a deal that is rarely optimal for the creative people involved screw with this principle. However, as we've seen, the Internet is a great tool for change and developing new business models. Copyright is going to benefit individuals more and middleman corporations less as time goes on. In fact, strong copyright laws and a cost-effective method of enforcement could be a great leveller to prevent megacorps with economies of scale and visible brands from freeloading by letting the little guys put in all the effort and then scooping up the work for distribution without any obligation to give fair compensation.
Replacing copyright with some sort of subsidy system based on general taxation, as you propose in your reply to my other post, severs any potential direct connection between creator and beneficiary. Instead, it would inevitably create some sort of political system, where some supposedly worthy person or organisation deemed a certain work worthy of a certain reward based on some artificial means or subjective judgement. Rather than creating more and better works and sharing them more widely, creators would then be incentivised to game the new system instead, because that is where the rewards would be found. Why would we adopt such a system when we already have a well-established and transparent way of letting the beneficiaries of works themselves make a direct judgement? We call that system "money", and copyright is a simple principle that lets us apply that proven system to creative works as well.
Incidentally, I don't think you've really thought through your proposed tax scheme very much at all, because it is fundamentally flawed in several other ways as well, not least that the bureaucratic overheads of administering such a system would be staggering. Paradoxically, it relies on the idea that people would continue to be able to sell derivative works for money, which seems highly unlikely in a system where by construction everything can be shared for free. Then there is the issue of identifying the beneficiary of the tax, which might be trivial in first generation derived works but would require an implausible amount of research in general: consider the case of Open Source projects that have wanted to adopt a new licence, but would have to identify every individual contributor whose code remained in any part of the system to seek their approval, or the current difficulties faced by the collective licensing bodies in sharing out the proceeds from public performances of works under copyright. Practically, your tax system could only ever provide a financial benefit to contributors to creative works by imposing even more hassle than exists today, which brings us back to no-one selling anything and therefore contributors gaining no financial benefit. Any way you dress it up, good will and a feeling of having made a difference do not pay the rent.
As for your economic assessment of copying creating more value for the economy as a whole, it is remarkable that someone so keen to elevate the debate to macroeconomic principles can only see the short term picture in this area. Of course the world would benefit today if we reneged on the copyright deal and released all current content to anyone who wanted it, without limitation. The world would probably still benefit tomorrow, too. But what about next month? Next year? Ten years from now? Who will make the future content, if you can't trust the promises made—by law, no less—and build a business model accordingly? It is obvious that copyright is damaging in some sense in the short term, but the more useful question is whether system works effectively over the long term.
As a final point, on the studies question, it is hard to debate without having specific points of reference, but obviously your experience is different to mine. In one of the last two studies I remember reading about, IIRC the conclusion was that in a certain country a slight majority of the population had infringed by downloading illegal content, which was the first time any report had identified an overall majority as infringers. In the other study, on the ethics of copying, almost everyone felt that private copying for personal use was fair and should be legal, but almost as large a majority felt that sharing with other people outside the immediate household was over the line and should not be allowed. I've long since forgotten the sources of these, but if I can find a bookmark I'll post again. In any case, if "most studies you've seen" really do consider sharing acceptable by such a wide margin, I have to question the methodology and what part of the population was being studied, because even the most generous of assessments I've encountered wouldn't support your claim.