In the early years of Bitcoin, anonymity or that capacity to send Bitcoin to anyone anytime and of course anytime without the need to identify the sender and the receiver was touted as one of the many advantages of dealing with this cryptocurrency. But then we realized this can be a wrong notion as all the transactions are recorded in the ledger or the blockchain and right now there are already tracking technologies that are looking for footprints to identify the possible sender and the receiver. Hence, we already have cases in courts of successful prosecution of illegal transactions using Bitcoin.
I just read this very good and very plain explanation about Bitcoin's anonymity and that it is in fact should be called as
pseudonymous where it is said that sending/receiving Bitcoin is akin to writing under a pseudonym.
Anyway, I am wishing you the best in your endeavor of writing an academic legal paper on Bitcoin & Anonymity.