There are pertinent articles regarding RA 9504 over at Punongbayan & Araullo’s Press Room. They describe the issues surrounding the law.
You can read the articles here, here, and here.
Many concerns have been raised, and my favorite:
Is this really what RA 9504 intended — to create and encourage absurd situations? Can’t the BIR, at least, read the real intent of RA 9504 and help promote social justice by saying that any income received by a worker over and above the minimum wage, to the extent that the tax distortion is eliminated and the take home pay is equalized, be still exempt from taxes as a MWE?
It may be difficult to justify such move, considering that the flaw is in the law itself. But the BIR was able to do it in certain instances in the past.
With these good, pertinent, and timely articles from an accounting firm website, P&A would have better hosted a discussion by offering comments or provided a forum. It would have been a good discussion, instead of just a lone standing article.