In future entries I’ll join the chorus of speculation on how the world might change during an Obama administration, but today I thought I’d share a perspective on prognostication itself.

Harry Truman famously said that he wanted to hire one-armed economists, so they would stop saying, “…on the other hand…”

A few years back, I read a fantastic description of the role of economists. I wish I could remember where I read it or who wrote it, because I’d love to give proper attribution to this beautiful explanation. If you know the source, please let me know through the comments section.

It goes like this: To understand the role of economists in government, imagine a baseball team that takes the field with 27 left fielders, each with his or her own ball. As soon as a batter makes contact, each of these left fielders throws his or her ball wherever he or she thinks it should go. Economists influence policy the same way those left fielders would influence a baseball game. I think it’s the best explanation I've ever heard.

Of course, that was before the advent of 24/7 cable news and the World Wide Web, so now I’m pretty sure the baseball team also has 22 center fielders, 38 right fielders, and a dozen pitching consultants on the mound. Anyone who reads multiple news sources each day, such as the New York Times and the Wall Street Journal, or Huffingtonpost.com and Foxnews.com, can instantly relate to this analogy.

Of course, this is not a slam at economists – they know they are making fallible predictions based on inadequate data and unknowable variables, trying to understand an extremely complex world. Politicians and the press just seem to conveniently forget that economists offer opinions, not prophecy. A few economists also forget this fact.

Despite the fact that we are usually wrong, it is important and useful for us to exercise our imagination and try to foresee all our possible futures. We may not be able to predict the future, but we must dream. As the song so aptly explains, “If you don’t have a dream, how you gonna make a dream come true?”

We know that our nation faces difficult economic choices in the coming weeks, months and years. But do we really know what we want a post-crisis economy to look like? What precisely is our dream?