The abstract is usually in the past tense due to it showing what has already been studied. Example: “This study was conducted at the Iyarina Field School, and within the indigenous Waorani community ...

Sometimes a fiction writer may use the present tense to make their writing more immediate, as in this example from The Time Traveller’s Wife by Audrey Niffenegger: ‘It’s hard being left behind.

Emerging studies demonstrate just why you should be careful to use the present tense if you wish to be more persuasive.