Economics is actually a fairly simple system to figure out (at least at the basic level, which is all you need to predict most things). The problem, rather similar to politics, is that people approach it from an ideological viewpoint, rather than from an objective one, and you therefore get ridiculous projections like that one that claimed that 60% of American households would have
two master bedrooms by 2012. This claim was made in 2006, recieving a great deal of mainstream publicity, while the economists who pointed out the coming economic collapse - of which there were many - tended to be confined to late-night television shows on obscure networks. I know; I watched many of these shows back then.
The economy of Nazi Germany was rotten to the core. Even its own economists recognised this.
Albert Speer, who ran the German economy from 1941 onwards, recognised this. While many of Speer's comments are self-serving, it's been corroborated that he argued with Hitler early and often about the state of the German economy. If a
non-economist with
no economic training (Speer was, after all, merely an architect with a knack for administration) could see how bad Germany's economy was in 1941, how much more obvious must it have been to a trained economist? Such as, say Hjalmar Schacht, one of Speer's predecessors as the Minister for Economy, who repeatedly warned both Hitler and Goering that their economic policies were disastrous, and who resigned in 1937 in protest over the rearmament program, which he warned would cause inflation (it did). He was finally fired from his sole remaining position - head of the Reichsbank - in 1939, prior to the outbreak of war, for once again protesting Germany's economic policies. And Schacht was one of those who
supported the Nazi regime.
The foolishness of Nazi economic policies was well-known among economists in the 1930s: it was just a case of
Nazi economists deluding themselves by approaching economics from an ideological viewpoint, rather than from an objective viewpoint based upon logical projections. Rather similar to how many modern-da economists argue that deregulation will solve every economic problem, while others argue that only with massive government intervention can they be solved. In reality, it's the people in the middle, who don't have an ideological viewpoint to push, who are correct in their projections, which is something that is historically proven.
Even Goering eventually came to the realisation that the German economy was rotten, which is why he argued for the
Anschluss and against war: he recognised that Germany needed raw materials in order to survive, but knew that it didn't possess the economic strength or industrial capacity to win a war against any of the major powers. The German victory over France surprised the hell out of him - as it did most people in the world - and enabled the German economy to hold out for far longer than it should have. But without Soviet backing and pillaging conquered territories, the German economy would have collapsed far sooner. Without the
Anschluss, it likely wouldn't have made it to 1940, without the re-militarisation the Rhineland, it wouldn't have made it to 1938, without the Munich Pact, it was doomed to collapse early in the next decade, and so on. The best thing that ever happened to the German economy was the Nazi-Soviet Pact. It basically gave Germany everything it needed to last for half-a-decade or more. That's the only way Germany's economy could have survived: by becoming an economic appendage of the USSR. How tenable do you think such a situation would be? To either side?
Economics isn't that arcane, red_elk. Specific occurences - the Poseidon mining disaster, the collapse in share prices after terrorist attacks - are unpredictable, but overall trends - the dot com bubble bursting, the housing crisis of the last few years - are not. Though one cannont predict the exact moment something will happen (just as one can't predict the exact moment rain will start to fall - it can always be narrowed down to a fairly measurable period of time, especially the closer you get to the event. You don't know if the dot com bubble will burst in 2000 or 2002, but it will happen somewhere in that period. You don't know if the rain will come on Saturday or Sunday, but it'll be wet sometime on the weekend.
Like everything, the more data you have, the easier it is to make accurate predictions. And the closer to an event in economics (just like in a weather forecast

) the easier it gets to predict Exactly when something will happen. I'll use your weather analogy, even though it's imperfect, to illustrate this for you. It's easy to predict that a hurricane will devastate New Orleans. Predicting exactly when it will happen takes more data. And every single long-term projection of the German economy shows that it reached the point of no return in 1937 at the latest. My personal opinion is that Germany passed that point in 1935, when it continued to favour the armed forces over the creation of consumer goods, when the armed forces had already served their purpose.
I hope this has been enlightening for you. I suggest a quick check of
Wikipedia pages devoted to the German economy of the period for further research. I'm only disappointed that most of the books on this aren't online, or I'd link to them for you.