One of these things is not like the others.
When you cut back on spending, it slows the economy down even further. Eventually, though, the economy recovers and you have more savings (or less debt).
Similarly, going to grad school during a recession takes you out of the work force at a time when there's less demand for workers. When demand picks up again, you have more knowledge and better credentials. You might be able to get a better job.
When people went into the military for the war in Iraq, as previously pointed out in this blog:
"Typically a bad economy has worked to the benefit of the military," retired Navy Rear Admiral John D. Hutson told the Boston Globe. But it's worked to the injury of the people who joined the military.