
The chart above shows a long term, secular, 140 year perspective between one of the two main rival asset classes - stocks and bonds. Bonds are presented as a 10 Yr Yield and the stocks are presented as S&P 500, adjusted for inflation. Here are some interest points to note:
Bonds
When one looks at the long term interest rate picture, it should become quite obvious that there have so far been five cycles known as Kondratieff Waves. These secular cycles are inflationary and deflationary in nature, and tend to last anywhere between 20 to 30 years. The two most recent ones have been an inflation cycle, where interest rates rise, which started in 1950s and ended in early 1980s. The other is the current deflationary cycle, where interest rates fall, which started in early 1980s and still seems to be in progress. Another obvious point is that weather the current deflationary cycle has already ended in 2008, or will end soon, one thing is for sure, next few generations will once again experience rising interest rates in a inflationary cycle.
Stocks
Share prices, on the other hand, tend to under-perform when interest rates are rising during an inflationary Kondratieff Wave. This was obvious during the early 1900s up to early 1920s, as well as during late 1960s up to early 1980s. Since the equity market (inflation adjusted) trades in the opposite direction to the commodities, it is therefore important to understand that during high inflation periods, where interest rates are on a rise, commodities tend to out-perfprom stocks. Consider that when equities enter secular inflation adjusted bear markets, commodities tend to enter powerful bull market rallies. As we can see from the chart below, when equities were depressed during 1860s, 1910s, 1940s, 1970s and 2000s, it was commodities climbing in an almost vertical line upwards.

Long term equity market moves are also very much connected towards valuations. The chart below shows the long term CAPE valuation method averaged over 10 years for the S&P 500. Therefore, the S&P 500's value based on decade of earnings, currently stands at a price to earnings ratio of 23.52. This reading is much lower than a ratio of 44.20, which was recorded in December 1999, just as the equity market bubble popped. This obviously tells us that the market is not extremely overvalued, compared to where it was.

However, it is important to realise that this reading is on par with the ratio of 24.06, which was recorded in January 1966, just as the equity market topped after a merger and takeover conglomerate boom came to an end. It is also worth noting that during the last 1890s equity market boom, by June of 1901, the market valuation based on this ratio was 25.24. Therefore both of these examples throughout history show that the current reading is on the overvalued side, where two previous secular equity market bull came to an end (1901 & 1966).
Conclusion
My long term outlook based on historical cycles (Kondratieff Wave) leads me to conclude that, over a secular long term view, the government bonds are currently the most overpriced asset class. Contrary to all the gloom and doom coverage, deflation talk comparing the United States to Japan, and constant double dip worries, I would stay away from any purchases of government fixed income, which is branded "flight to quality / flight to safety / risk off" asset.
The stock market, on the other hand is not extremely overvalued (bubble) and just like in early 2009, has the ability to produce strong cyclical returns, however over the long term, I think that the stock market still has several years of this secular bear market to go, where it will move south in both the inflation adjusted price, when compared to the 2000 top, as well as in valuation terms, when compared to the CAPE10 ratio. Most secular bear markets bottom with single digit CAPE10 ratios, instead of the ones in mid-20s. As commodities tend to move in an opposite direction to equities and also benefit from an inflationary rise in interest rates (Kondratieff Wave), that still looks like the most attractive investment asset class. That does not mean you run out and buy commodities tomorrow, but time your entry on any major correction or consolidation.
Long Term Investment Summary: Sell/Short the 30 Year Long Bond for years and years to come, own real assets like Commodities or Commodity Producing Equities due to up-and-coming inflationary cycle which should last for decades to come. Instead of doing business degrees in university, consider working in farming or mining sectors of the economy. Do not work on Wall Street as a Bond Trader / Manager. Stay away from debt as rising interest rates will become a huge headwind. Equities could become cheap once again within a several year time frame, if and when the CAPE10 enters single digits.