Modern mainstream economics 

The modern mainstream economics section repeats itself a lot.

It opens with "Mainstream economics begins with the premise that resources are scarce and that it is necessary to choose between competing alternatives."  this is a reiteration of something found in the opening of the article - "the science which studies human behaviour as a relationship between ends and scarce means which have alternative uses."  Someone must really like repeating that though because later on in this section we see 

"Economics studies how individuals and societies seek to satisfy needs and wants through incentives, choices, and allocation of scarce resources."

Then later in this section we see

"neoclassical economics, which began to develop in the late 1800s and models choices made in the allocation of scarce resources."

Then later in this section

"It is sometimes referred to as the study of choice under conditions of scarcity."

Then later in this section

"Economics is a broad term given to the social science of how choices are made in face of limited resources."

Then later in this section a word for word repetition of what was said in the opening -

"the science which studies human behavior as a relationship between given ends and scarce means which have alternative uses"

Reading all of this I conclude that mainstream economics studies the relationship between given ends and scarce means which have alternative uses.  But I do not need to be told this six times (seven, if you count the opening).  This section also repeats itself in other ways.  I am removing redundancy from it.