Briefly summarize the current situation and proposed change
Don't presume the reader already knows all the relevant details. The memo
should be understandable to someone who hasn't been in the loop.
Briefly explain key results
Indicate how you obtained your results, don't just put in a bunch of
Place tables and figures after they are first mentioned in the text.
The reader shouldn't run into a table or figure until after you've let
them know it's coming.
Consider using pie or bar graphs to illustrate your numerical results.
However, only do it if it adds something and isn't trivial: no bar
charts with just one bar! Also, be sure to include a title, labels for
each axis, and indicate any relevant units.
Watch out for incorrect but correctly-spelled words.
Be aware that spelling checkers won't stop you from accidentally using
an incorrect, but correctly spelled, word. An example that often comes
up in these memos is "lose" vs. "loose".
Lose is the opposite of "win", and almost always the word that belongs
in the memo: e.g., "consumers lose $1B as a result of the policy".
Loose is the opposite of "tight". It's probably NOT what you mean
unless you are writing about loose regulations.
Write in 3rd person unless you really know what you're doing.
Writing in 1st person can make a document more lively and readable but
it has to be done carefully to avoid being confusing or condescending
toward the reader. Under no circumstances use "we" unless you are part
of the organization to
whom you are writing (and in memos written for this class, you are not
part of the organization -- you are an outside consultant). Also see
the "Don'ts" section below on why it's good to avoid second person.
Be sure your pronouns agree with their nouns.
In formal American usage, organizations are treated as singular. This is a little tricky because it's different from usage in the UK and elsewhere, and because people don't always follow the rule in informal speech. Here are a couple of examples:
||Apple reduced the price it charges for the iPhone.
||Apple reduced the price they charge for the iPhone.
||Tesla is going to announce a new car on Tuesday.
||Tesla are going to announce a new car on Tuesday.
In informal settings, people are often inconsistent: they use singular when no pronoun is involved ("Tesla is...") and plural when a pronoun is present ("Apple ... they charge..."). However, formal writing should be consistent: stick with singular or plural throughout. If you don't go the singular route, be aware some sentences ("Tesla are ...") will look like mistakes to an American reader unless the person is aware of the difference in usage and also knows (or suspects) that you're not from the US.
No matter where you're from, the verb should agree in number with the noun or pronoun. The following are wrong everywhere: "reduced the price it charge" or "reduce the price they charges".
Focus on stating the facts and try to avoid including too many adjectives that might overstate your case or suggest that small differences are more important than they are. For example, don't say a policy imposes "huge" costs or creates "enormous" benefits unless the costs or benefits really merit the adjectives.