**try to write the introductory paragraph again. Try to make it about 4 to 5 sentences.
One school in Chicago implemented a policy to reward students based on 1) their grades. However, after one year, the school was forced to discontinue this policy due to the lack of funds. 2) Though this policy 3)is effective, it is short-lived; the cost of this policy is not possible for schools to uphold. Some 4)may argue that reducing the amount of cash rewards the students receive would 5) solve the problem. 6) This would also result in the decrease in effectiveness of this policy. 7) As students do not find the cash reward appealing, they would not be motivated to study, which diminishes the purpose of the policy. 8) Thus, this policy would not be sustained for long.
1)Too vague. Be more specific. e.g. for A's and B's. Where's the citation?
2) I prefer "although" to "though" at the beginning of a sentence.
3) Tense switches here. Maintain tense or transition appropriately. Citation?
4) The use of "may" is weak here. Remove. Think about creating another paragraph here.
5) Would it "solve the problem" or "lengthen the program's duration?"
6) You are trying to make a "however" point, but you are unclear.
7) Conditional sentence without the conditional tense. "If students do not find the cash reward appealing, they would be less motivated to study."
8) Conclude with a summation that the program is impossible to sustain in a large urban school district.
Based on a study 9)made by Massachusetts Institute of Technology, money is 10) not a very effective motivator. If a task is simple, straightforward and involves only mechanical skills 11); then a higher pay would result in a better performance. 12) However, if the task is complicated that requires conceptual, creative thinking and involves rudimentary cognitive skills; it would not be successful at all. Instead, it would be the complete opposite! Many studies have also proved that recognizing 13) student's accomplishments is 14) the ultimately the best motivator. According to Sylvia Rimm, a child psychologist, consistency plays a 15) much more major role in achievement than money does. 16) For example, top students would also try to maintain their results with consistent effort. Whereas, others who failed give up easily as they find that there is no hope in them getting rewards and compliments. Therefore, money is not a good motivator.
9) "Made by" to "by researchers at the"
10) "an ineffective motivator."
11) Change the ";" to ","
12) "On the other hand, if the task requires creative thinking and other higher cognitive skills, then performance is not correlated with pay."
14) Remove "the"
15) Change "much more major" to "more important." Citation?
16) Change to "She found that students previously rated as 'high-performers' showed consistent effort to maintain their status, whereas students rated as 'low-performers' showed less effort to maintain theirs."
17)"It is also wrong..." Try to avoid this construction in an argumentative essay. Labeling something as "wrong" does not make it wrong.
18) Avoid run-on sentences. "...to lure students into studying by using cash as it gives them an idea that everything revolves around money which is a bitter truth that they are too young to learn." Break up this sentence.
19) "Students may focus too intently on outcomes and assume that good grades equal earnings, not learning." Suggestion
20) I enjoyed reading about the three factors. They make sense.
Overall, I feel that you have good evidence and research, but your analysis is a little weak. Try to ask yourself questions about the studies you read. Can you think up a scenario and apply something you learned to solve it? Also, try to stay in the present tense as much as humanly possible. Very good start.