and range of thinking that bears on research and all of that would be a healthy development >> steve leasemanit looks at the stock market it goes up triple digits in the dow jones to what extent are there concerns about current market evaluations or if we keep going, should that animate monetary policy finally, maybe as a sign of what's been going on with valuations, this crib to currency called bitcoin keeps going up every day what is the policy of the central bank of the united states, the introduction, use, and incredible rise in popularity of bitcoin. >> okay, let me start, steve, with the stock market generally. i mean, of course the stock market has gone up a great deal this year and we have in recent months characterized the general level of asset valuations as elevated with that reflects is simply the assessment that looking at price earnings, ratios, and comparable metrics for other assets, other than equities, we see ratios that are in the high end of historical ranges. and so, that's worth pointing out. but, economists are not great at knowing what appropriate valuations are and we