Has the European Union been effective in representing the diverse population of the Euro- zone
This isn't a question with a definite "Yes" or "No" answer. To answer it, you will need to find and read materials about the subject and reach your own conclusion. You can use library resources to learn about the subject.
For books, follow the link below to the library's book catalog and search for su:European Union. There are some books and a lot of eBooks on the subject.
For articles, follow the link below to our Databases by Subject guide. The databases under the Hot Topics & News tab are likely the best for finding material about this subject.
Among those databases, CQ Researcher and Issues & Controversies are both good for getting articles that give overviews of the subject and common arguments made about it. For more detailed articles, Academic Search Complete is the best place to search. In Academic Search Complete, you can retrieve all articles about the European Union by searching for DE "European Union". This will retrieve thousands of articles. You can reduce this number by using the options on the left (full text, source type, publication date, subtopic, etc.). Since you are writing about the current state of the European Union you should limit the search to articles published in the past few years. You also can make your search more specific by adding additional search criteria, like DE "EUROZONE" AND DE "European Union".
There are also some videos on Films on Demand about the European Union that you may find useful. You can reach Films on Demand through the link below.
You can learn more about using the individual databases through the How to Use Hot Topics Database Libguide linked below.