As we know Mr Birling does not regret anything he had done,there is no hope that he would change in the future.This is because he did not learn anything from what he had done and when they were learning something they came to know that the inspector was a fake.Mr Birling was only worried about public scandal and his knighthood and needless to say he would not change at all.
Gerald has a chance of changing as he learnt and came to know that he broke sheila's trust and he wants to make up for that so maybe he can change.
Eric of course has a hope and we see that he has changed.This is because he learnt a lesson from what he had done and does not care if that person was an inspector or not ,he just knew that he confessed and did something wrong which was no less than a crime.Like sheila eric had also become wiser and more socialistic.
