The great thing about the internal assessment for IB economics is that it uses the same three skills as the essay and data response questions (see the page on “Answering IB-style Questions” for more information on these three skills).
First you should define a couple of terms that are either explicitly or implicitly in the news item you are commenting upon. For instance, if your article was about a firm charging different customers different prices for the same good, you would be wise to define “price discrimination” even if the term itself is not actually in the article.
Next, you should move onto some analysis. Generally, you should introduce, draw, and then explain two diagrams. The cleanest commentaries tend to be about articles that talk about a policy solution to a problem, such as the central bank raising interest rates in response to an increase in the rate of inflation. The two diagrams that make a lot of sense for an article such as this would be one illustrating the problem of inflation and another illustrating the solution of raising interest rates. Each diagram should be introduced with a couple of sentences explaining the situation being illustrated, and should be followed by a couple of sentences which clearly, and with reference to specific points on the diagram, explain what the diagram shows.
Lastly, your commentary should feature evaluation (and lots of it). The goal when defining your terms and doing analysis should be to do them as efficiently as possible so as to leave as many words as possible for evaluation. Using our inflation/interest rate example again, you could easily write 500+ words evaluating whether higher interest rates are likely to reduce inflation and looking at the other impacts of higher interest rates on consumers, firms, workers and the government in both the near future and in the more distant future. At the end of your evaluation, looking at the situation in its entirety, you should then make a judgment as to whether the decision to raise interest rates is a sound one or not.
The key to a good commentary is having a good article that looks at a problem and suggests a policy solution, as that allows you to evaluate the suggested solution. Once you have a good article, planning your writing can really help you to write in a more organized and clearer fashion. Please click on the first link below to see a commentary planning sheet which you may find helpful. Lastly, click on the second link and have a look at a model commentary I have written which I hope will make clear to you both what the process and the finished product should look like.
Workbook for the New I.B. Economics by Bryce McBride is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.