Quote from whitster:
"get S&P data starting back in the Fifties and calculate a moving standard deviation for them"
Bull.
VIX measures implied volatility. It does NOT MEASURE VOLATILITY of the UNDERLYING (which is what you would get from above), it measures the IMPLIED volatility. IOW< the volatility encompassed within the premium/pricing strucutre of the OPTIONS on the underlying (the S&P100)
Definition: "The Chicago Board Options Exchange Volatility Index, or VIX is a popular measure of market risk. It is created with the implied volatilities of a variety of S&P 500 index options"
The whole point of the VIX is that it does not merely measure the volatility in the underlying. this is CRITICAL to understand. it measured the IMPLIED volatility
The CBOE did not have an option on the S&P 100 until 1983
so, again.
there was no VIX 50 years ago, nor would measuring voltility in UNDERLYING tell you how people were pricing options related to the underlying. that is what implied volatility means.