A 1992 study showed that "52% of surveyed students indicated having a moderate to high need for help concerning procrastination". It is estimated that 80%–95% of college students engage in procrastination, approximately 75% considering themselves procrastinators.

"Student syndrome" refers to the phenomenon where a student will only begin to fully apply themselves to a task immediately before a deadline. This negates the usefulness of any buffers built into individual task duration estimates. 2002 study results indicate that many students are aware of procrastination and accordingly set costly binding deadlines long before the date for which the task is due. Furthermore, these self-imposed binding deadlines are correlated with a better performance than without binding deadlines, though performance is best for evenly-spaced external binding deadlines. Finally, students have difficulties optimally setting self-imposed deadlines, with results suggesting a lack of spacing before the date at which tasks are due. In one experiment, participation in online exercises was found to be five times higher in the final week before a deadline than in the summed total of the first three weeks for which the exercises were available. Procrastinators end up being the ones doing most of the work in the final week before a deadline.

Other reasons cited on why students procrastinate include fear of failure and success, perfectionist expectations, and legitimate activities that may take precedence over school work (like a job).

Procrastination has been associated with the later submission of academic papers, as would have been expected almost by definition.[14] Additionally, procrastinators have been found to receive worse grades that do non-procrastinators. Tice et al. (1997) report that more than one third of variation in final exam score could be attributed to procrastination. The negative association between procrastination and academic performance is recurring and consistent. Howell et al. (2006) found that, though scores on two widely used procrastination scales were not significantly associated with the grade received for an assignment, self-report measures of procrastination on the assessment itself were negatively associated with grade.

Procrastination is considerably more widespread in students than in the general population, with over 70 percent of students reporting procrastination for assignments at some point. A recent panel study from Germany among several thousand university students found that increasing academic procrastination increases the frequency of seven different forms of academic misconduct, i.e., using fraudulent excuses, plagiarism, copying from someone else in exams, using forbidden means in exams, carrying forbidden means into exams, copying parts of homework from others, fabrication or falsification of data and the variety of academic misconduct. This study argues that academic misconduct can be seen as a means to cope with the negative consequences of academic procrastination such as performance impairment.

There may be multiple motives that underlie procrastination besides avoiding something expected to be unpleasant or result in failure, such as the excitement of getting done under the wire. I think the jury is out to date on this one, but  check out work by Freeman http://link.springer.com/article/10.1007/s12144-011-9123-0

And also a nice meta-analysis by Steel https://www.researchgate.net/publication/222402939_Arousal_avoidant_and_decisional_procrastinators_Do_they_exist

On a relate note, you might also look into planning biases in initiating and completing tasks, and aspects of personality that might predict their degree, direction, and magnitude -- see further in the two Pezzo & Litman papers http://drjlitman.net/?page_id=156

Article Arousal, avoidant and decisional procrastinators: Do they exist?

I can recommend a study that compares self-report and behavioral measures of procrastination:  

Krause, K., & Freund, A. M. (2014). Delay or procrastination–A comparison of self-report and behavioral measures of procrastination and their impact on affective well-being. Personality and Individual Differences, 63, 75-80.

See pdf in my profile (if you can help) :

- Filippello, P., Sorrenti, L., Larcan, R., Rizzo, A. (2013). Academic underachievement, self-esteem and self-efficacy in decision making. Mediterranean Journal of Clinical Psychology, 3, 1-11. ISSN: 2282-1619. Doi: 10.6092/2282-1619/2013.1.934. 

- Filippello, P., Sorrenti, L., Cuzzocrea, F., Nuzzaci, A., Larcan, R. (2014). The Subtle Sound of Learning: What Are the Roles of the Self-esteem, Decision-Making, and Social Skills in Adolescents’ Academic Performance? US-China Education Review B, Vol.4, No.2, 73-85. ISSN 2161-6248.