Culmus
The implied growth rate in the Barra model is a historical number, rather than one based on analysts' expectations. Here is how Barra describes it:
"The capitalization-weighted average of the individual constituent growth rates. The individual company growth rate is the 60 month average of the historical EPS growth, a function of return on equity and retention rate."
Because it is a rolling 5-year number, it will lag badly. If you look at the long-term ROE chart, there has been an upward trend coincident with the great bull market dating back to 1983. However, ROE peaked around the same time as the market, and has rolled over sharply. Interestingly, ROA does not show the same long-term uptrend as ROE, implying that corporate leveraging was a major driver in higher ROE and stock prices. That game is now over, as I think you have pointed out before. So...a different interpretation but the same conclusion.