You're right it isn't longitudinal as you're not following up a cohort of specific people. Similarly it's not retrospective as that's like a backwards longitudinal.
It does depend on the data you have, and whether your exposure (being on the receiving end of policy) is measured at the individual level or the population level. Ditto the outcome (employment status).
I would say that if you are looking at individual people and what policies were targeted to them, and what their employment status was, it's a serial cross sectional study (i.e. repeated snapshots, different people at each measurement point).
If, however, you are just looking at population level changes in policy, and population level changes in employment at different time points, then I would say it was an ecological/correlational study (http://en.wikipedia.org/wiki/Ecological_study). Be careful what you infer from the associations as you do not know the 'exposure' and 'outcome' at the individual level.
I suspect the latter is more likely.