Is there a quote for Gerald to support that he is a capatalist?

There’s a good deal of silly talk about these days—but—and I speak as a hard-headed business man, who has to take risks and know what he’s about—I say, you can ignore all this silly pessimistic talk. When you marry, you’ll be marrying at a very good time.

Thank you but Birling say's that and not Gerald.

I think it is more implied, If there is an explicit quotation, I don't think it can be much more effective than the way Gerald agrees with everything that Birling says, and Birling definitely opposes socialism - "Probably a Socialist or some sort of crank". However, too many, Gerald is a much more likeable character than Birling and, whereas I can see where they are coming from, they fail to see that when Birling fired Eva Smith, he was merely doing his job and that it didn't really affect her as she, like anyone else in her position would have done, got another job. Ultimately, if you put the characters in rank order of responsibility for Eva Smith's death, Priestley wants you to rank him somewhere high and it is obvious that the play is full of bias but in reality, Birling should be somewhere at the bottom. It wasn't just in 1912 or 1945 that people got fired. It happens everyday. You need to be able to see that Birling is actually a softer character than Mrs Birling, who also appears cold and emotionless, but in reality, again did her job. If you were in Mr Birling's position today, and somebody had started a strike demanding more money and it failed, they would be fired. Similarly, if you were in Mrs Birling's position and somebody came to you spinning a pack of lies and it is obvious as they dared to use your name, you would reject their application for help. For a higher grade, you might consider yourself taking the position of the 'devil's advocate', although you have to ensure you see what Priestley is doing and why and appreciate his side of the argument to get all the marks. In addition, you need to be able to reason why this is ineffective, and this is largely due to the huge volume of bias Priestley has flooded throughout the play to make his point. Really, I think playing 'devil's advocate' here is more like looking at this play objectively and then being realistic.