Students are always trotting out the 'improve education' answer, but few do this is in a particularly specific way, and even when they do, they tend to stick to arguments about school funding or tuition fees. Discussions of adult retraining are often ignored, but there are some superb arguments to be made on loads of fronts: human capital, agile labour markets and structural unemployment are just a few area where adult retraining could be useful.
Economics Observatory have a great analysis on adult education and retraining. It's a really good example of how economists unpick a question, and is also a good introduction to referencing. Your students might also want to know about the policies the government have actually proposed in this realm, so you might also want to take a look at the Skills for Jobs White Paper. It looks a bit daunting at 77 pages, but you can show students how, with big reports like this, we can usually start with the executive summary, and scan that for the parts we're interested in. In this case, the policies are summarised under 'Summary of Decisions' which are on pages 12-15 of the pdf (marked as page number 9-12).
I've come up with a few activities to try and get students to process the information and spend a bit of time thinking about it. You can get that below: