What could be a concluding sentence for a persuasive essay arguing that teachers should assign less work?

Here's another possible ending that builds on the comments in this thread:

The goal of education should to be to sharpen important skills and to increase knowledge, not to produce mounds of used paper. We should focus on quality, not quantity.

When I end my own essays, I like to have something that is absolutely on topic, that summarizes my main argument using new words or images, and that maybe even leaves the reader with a smile.

There is a perfectly valid formula that you can follow (see the link below to an eNotes post) that is built around a restatement of the three-part thesis, but that method may come across as a little too canned or formulaic. Maybe draft two or more endings, show them to a few people (including teachers), and then decide on which might best fit the essay.

In the conclusion of a persuasive essay, it is standard, good practice to restate your thesis (your statement of position), summarize the points of persuasion that you discussed within the body of your essay, and then, in an essay like the one you are writing, to end with a call to action.  The purpose of persuasion is to cause a change of thought within the reader or have the reader actually DO something.  If your paper is dealing with persuading teachers to assign less homework, then I'm assuming that your audience (who is is that you intend to read your paper) is teachers in general.  A good conclusion, then, would ask them to do something - in this case, give fewer homework assignments.  The answer from ashwang incorporated this, as well as another highly effective technique for persuasion, direct address, where you speak directly to the reader.  A good concluding sentence, then, would be a call to action using direct address.

I think that it might be effective to talk about how the modern student is a stressed one.  With so much emphasis on high stakes standardized assessment, teachers and administrators might mistakenly place too strong of an emphasis on homework.  I think that it might be effective to talk about how this ends up being shouldered by the student and that it might be good for teachers to recognize that while content instruction is important, education should be geared towards developing "the whole child."  In this notion of self- actualization, minimizing homework might enable moments in which students could actually enjoy some of their time outside of school and not be inundated with hours of homework a night.  It might be persuasive to speak and close your essay with an analysis of this emotional component in the lives of students.  There might be a call to teachers in acknowledging the inordinate amount of stress that the modern student faces. Much of this is based upon the standard of education that places so much emphasis on production and test results.  The one element that can be controlled in this configuration would be teacher assignment of homework, and this might be persuasive in the closing of your essay.