How to write a course application?

Hmmm, I would start by writing some notes, to form the basis of your application:

What are you particularly good at? (your strengths – I’m thinking more generally, like quick to grasp new concepts, looking at things from different angles, challenging things etc)
What is it about economics that you love, and that you excel at?
What would you dearly like to know more about, that being in the Honour Economics class would potentially give you?
What do you hope to do when you finish at this school?

In writing the application, I would then write up the notes above, pretty much in the same order – so starting with general good things about you, moving to the specifics about the course, and finishing with your hopes for the future.

I would start with I wish to be admitted into the Honors Economics program. I would be a good candidate for the program because…then state your reasons, give examples that demonstrate solid subject understanding of economics, and end with something about your goals.

Use words that indicate solid commitment. “I am interested…” is much stronger than “I think I would like to…”

Essentially, it’s a persuasive writing piece.