I did some extensive testing on corporation reputation changes.
Assuming game client is patched to 3.1, you will get somewhere between 5% and 15% reputation increase at rank 0. When you complete your first mission your reputation is established at 55%. The next mission will put you into 60, 65 or 70%. If you reload prior to completing the mission, you will receive random increase (which is extremely profitable at rank 0). For instance, I just started with Atreus - second mission was a "follow to their base" one. I was at 55% after the first assassination mission, now I'm at 70%.
I can confirm this behaviour for at least 3 factions (Strong Arms, Duke's and Atreus; all started in 3.1 patch) - I'm not doing combat missions, and since cancelling them is bad for the rep progression, I used this "feature" extensively to get to rank 2 ASAP - since cancelling missions at rank 0 and 1 deals a major impact on your rep. At rank 2 and 3 it's already much less in proportion of what you're rewarded when you complete a mission.
At rank 10, cancelling a mission doesn't reduce rep. at all
EDIT: Just did my third mission from Atreus. My rep prior to accepting was 70. it was a taxi mission. I reloaded a number of times to gamble a 15% increase, it went like this:
Code: Select all
Attempt Rep increase
1 5,00%
2 5,00%
3 5,00%
4 5,00%
5 10,00%
6 10,00%
7 5,00%
8 15,00%
Even if the next mission is a combat one, I'm safe to cancel it (for 5% decrease) and still retain 10% from the previous mission reward (I would go back to 70% if I didn't reload).