opening 

There seems to be a constant push to put neoclassical economics in the opening and make it seem like this covers all economic theory.  I don't know if this is due to ignorance or design or both.  At least this time it's in the fifth paragraph in stead of the first.

Calling neoclassical economics modern economics is hopelessly POV.  People who agree with the theory are "modern", what are people who don't, antiquated?  This was called mainstream economics, and it was changed to modern economics.  Since the person who changed it complained they did not like the phrase mainstream economics, I am changing it to neoclassical economics.  It is fine if you don't like the phrase mainstream economics, whoever called it that in the first place, but dividing economic theories into modern and implictly antiquated for the rest is POV.

Then there are the three sentences following that which detail neoclassical economics.  Neoclassical economics is one theory, your favorite, among other theories, and putting it at this point means to me that the paragraph describing the difference between these theories must proceed it ("Another division is between mainstream economics, used to distinguish economics in general, and heterodox approaches...") so people understand they are reading one approach to economics, not *all* approaches.  

Someone wanted to put this neoclassical stuff in the opening and use 75 words for it.  I think it is better to not go into it in the opening, but whatever.  But if it is put up there, the alternative, original theory of value deserves more space up top as well.

Then we have the modification of "that economics primarily deals with the exchange of value, and that labour (human effort) is the source of all value." to the ridiculous "Thus, in Marx’s labour theory of value, value is considered as a measure of labor exploitation, rather than of price."  This makes no sense on many levels - does this mean Marx thought an object produced without labor exploitation would have no value?  The idea that labor is the source of all value was not an innovation by Marx - Adam Smith, David Ricardo and all the early economists agreed on this and Marx simply accepted it.