timppu: Good suggestions, would they be universal or to be applied (or not) on different countries? If some countries choose not to apply them, how to force them, or prevent companies to make business from those countries? ...
Higher coporate taxes are in principle possible for every country. It was the case in the past until (stupidly) countries tried to make the tax system easier but only achieved to make it more unfair (probably due to lobbying and bribery of the corporations). Before you had to pay taxes for the business you conducted in a country, now you pay taxes in some country of your choice where you artificially put your headquarter and you avoid paying many taxes at all.
Basically the principle must be that each business pays taxes where it's customers are, not where it itself is residing. Very simple and clean. This way every country can decide how strongly to tax. And the countries should have the stronger stick. At the end they can for example threaten Google that they will forbid Google to conduct business in their location, if Google does not comply and hand over the taxes. That's also why I really like that GOG now pays VAT in the country of the consumer - I think GOG before actually did fraud. And Apple should pay billions of dollars of taxes each year in Europe alone - but they don't - this makes me mad and hating Apple.
So, I think there solutions are not too difficult, possible and not dependent on every country doing the same. Nobody needs to be forced outside of your country, but only inside the tax rules must be changed. Why this is not yet fully done many years ago - I don't know. Must be that politicians are all corrupt and bought by the corporations.
For the financial transaction tax this is a bit more difficult. It's more effective, the more countries take part in it. But even if just a bunch of countries start with it they will feel an impact. They cannot force others, but they can surely make trade agreements and other stuff dependent on an agreement on the TOBIN tax. So this is more difficult, and looking at the TTIP negotiations you rather get the impression that standards are to be lowered, not raised - which is rather sad. But in principle these negotiations would be the best chance to convince others.
For example you would think that London as an important financial market place is holy to the UK, but it isn't. A possible EU exit next year is threatening the position of London and in possible negotiations after the exit one could demand even more regulations of offshore tax heavens for example.
It's all not easy, but I'm convinced more can be done than is done now, because in principle countries have more pull because they can forbid businesses to conduct business if they do not comply with their rules. It doesn't mean you force others though. This is an important distinction.
Application of this principle for example on Luxembourg would read: If companies want to pay in Luxembourg - fine, but they also have to pay in France, Germany, Italy, ... and this means that in the end there is no advantage anymore of paying in Luxembourg, so they will only pay in Luxembourg what business they do there, which should not be very much and people in Luxembourg have to find real jobs (outside of the money tax evasion business) but people from all the other nations will benefit from the higher taxes and even corporations of the other nations (those who cannot do the same) will benefit from a fairer taxation.
.. This may have been a bit OT for the thread but you asked.