Kudos to someone who usually I don't agree with for calling this a year and a half ago, but I feel comfortable, now half-way through 2010 declaring that we are in a depression.
Economists have no quantitative definition of depression (which is ironic given that mainstream econ is nothing but a series of mathematical definitions and assumptions). Some say it's only when GDP fall by double-digit percent points, others have other definitions, still others have no real definitions - stating that the 1930s were the one and only 'depression'.
I would personally like someone to come up with the 'richter scale' for recessions...or at least the terrorist color grid: Code yellow, code orange, code red - defined by unemployment, underemployment, under-capacity, bank reserve hoarding...some combination thereof.
But, absent this, I would like to offer the following definition:
A DEPRESSION is "where unemployment or GDP growth is under typically defined 'full' levels for a period of time that exceeds the norm of the generation."
For my generation, the average economic recession lasts less than a year. This recession has gone on for 2.5 years SO FAR - with no turnaround yet projected for employment for months to come yet. Hence, we are in a depression. Maybe you are thinking, 'well duh.' If so, good for you. You shouldn't need someone like me pointing out the obvious to you.