My company, which is top 15 in terms of size, spends about 25% of turnover on R&D, that's about $5bn a year. I think most of the serious 'innovative' companies spend at least 20%. It is estimated that the total industry spend on R&D will be over $140bn this year. It's a very collaborative process, firms work with each other, academia, start up biotechs, whoever to find stuff. But it's how productive this spend is that's important. Most of it produces nothing except data about what doesn't work (useful in itself), rather than effective and safe medicines. So if the G20 put in £1bn each you would certainly add to scientific knowledge, but not necessarily any cures. This is why the private sector takes the risks and tries to charge as much as it can get away with for the relatively few products we actually get to sell, for the limited patent lives we have to sell them in. We do all right out of it though.