How come one person usually pays for everybody in Korea?

-Oh, I also thought that was very strange at first. I think the oldest person always picks up the bill.
- Well, you can consider (1)it just a part of Korean culture. However, (2)it's changing these days. Many young people like to pay individually. We also take turns paying.
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Q1: What does (1)it refer to?
Q2: what does (2)it refer to?
Does each 'it' refer to the same thing?

In both places, the word "it" seems to refer to the custom that's described in the sentence just before. There is not one single word for each pronoun to refer to.

To determine what (1)it and (2)it refer to, we need to carefully examine the context provided.

In this case, (1)it refers to the practice of one person usually paying for everybody in Korea. The speaker suggests that considering it just a part of Korean culture is one perspective on this custom.

On the other hand, (2)it refers to the changing trend where many young people in Korea prefer to pay individually or take turns paying. So, (2)it refers to the change in the traditional practice of one person paying for everyone.

Therefore, each 'it' refers to different things. (1)it refers to the traditional practice of one person paying for everybody, while (2)it refers to the changing trend of individuals paying separately or taking turns to pay.