I have just started a PhD along with another candidate. We are each looking at different aspects of the same subject. His data provide context for mine, while my data simply add value to his. As I will be asking him for some of his data, he has decided that he wants some of my data. However, he is interested in using a particular part of my data which I think will be the most fruitful part of my PhD.
His data are quicker to prepare than mine, and he will undoubtedly write up his chapters/ publications before I get a chance. I am worried that this will have a negative impact on my ability to publish my papers.
Do I have to give him my most promising data? Is there any way around doing this? I would prefer to rely on older data from Honours students looking at this subject and not ask for his data, if this allows me to keep my own data.