Just to review, the Great Depression in the US in the 1930s was rather horrid. Unemployment at 25%, wages low, people hungry, in worn shoes and clothes, living off the kindness of family, scratching out a living. However, many more people lived on farms back then, so they could provide susbsistence living. Should a depression occur now, we'd have that many more people totally dependent on others, with no means to even feed themselves. (And we have a lot more weapons now too. Will crime be a horrendous problem if we have another depression?)
One author is optimistic that emerging economies won't have a crisis like we did in 2008. That was sparked by too much savings chasing risky investments in pursuit of return. Emerging markets are riskier and give higher returns, so they might seem vulnerable to fright-and-flight in a crisis. But that's less likely for two reasons: 1) Emerging markets are now a standard part of large portfolios, not just a high-risk high-return asset, and 2) local investment pools are larger and will grow even more as pensions become important in emerging countries.
Another article isn't optimistic. It's about a world swimming in debt, with little hope to pay it off. Somehow I'm overly worried about this. I figure everyone takes a haircut, tightens their belts, and lives, though less lavishly.