In daily writing, I normally use the possessive form as "shareholders' wealth" or "firms' cash holding", but it seems that in research, I did not see people use the " ' " for possession if the subject is not human beings, similar to how my English teacher guided me, except this paper:
Our identification relies on the difference-in-differences estimation based on a staggered passage of leniency laws in 63 countries around the world from 1990 to 2012. In addition to exploiting a leniency law passage in the firm’s country, we look at the leniency law passages in the main export markets of the firm’s industry, and leniency law passages in the firm’s subsidiary locations, and find consistent results.
Would "wealth of shareholders" or "cash holding of firms" be suitable in academic paper writing or I can stick with "shareholders' wealth" or "firms' cash holding"?