system
Given the following post, respond as if you're commenting on Reddit:
human
Global Minimum Corporate Tax

Recently, country members of the G7 reached an historical deal that is a step towards an agreed global tax on corporations having a revenue margin of, at least, 10%. The purpose of this tax is to mitigate fiscal revenue losses due to " tax erosion and revenue shift" maneuvers. However, many experts are questioning the fairness of a global tax reform and many questions remain unanswered.

1. How does a global corporate tax work?
2. Who is affected by it?
3. Who receives the revenues of a global tax?
4. How are countries, such as Switzerland that have lowered their corporate tax to be competitive, affected by such a global fiscal policy?
5. Who enforces it?

This post is not about whether or not one agrees with a global tax, therefore, it is asked that any response to the above questions should be rooted in analysis using economic principles in order to give an honest inquiry on the subject.
gpt
It's not a "global" corporate tax where the world has a tax on corporations. Countries in the G7 have agreed to have a minimum tax on corporations at 15%. Corporations in these countries will not pay below the 15% minimum.   
Economics is all about incentives. For example, if city A substantially raises taxes on businesses, but cities B and C lower taxes, companies will move to B and C. However, city A still needs tax revenue to pay for a new infrastructure project. City A negotiates an agreement with the cities that lowered taxes to have a minimum tax similar to city A, so businesses won't have such a significant incentive to move.    
The Biden administration wants to increase the US corporate tax rate to pay for domestic spending (like his infrastructure and family plan). However, higher corporate taxes affect incentives and make it more expensive to operate in the United States. The global corporate tax rate will make it more difficult for countries like Ireland (with around a 12% tax rate) to compete with higher corporate tax rates. Basically, it stops a "race to the bottom" where countries cut taxes more than others to incentivize businesses moving there.