I don’t know exactly how Beck produced his numbers, but he did mention that his numbers were adjusted for inflation, so folks who bought homes for $20K back in the dark ages would show up as a higher number after adjusting to today’s dollars.
For the poster who said that prices were below the (flat) long term trend line for 20 years back in the 30’s and 40’s, so why can’t they be at 170 (above the trend line) for the next 15 – you are right, it is possible. Prices can be above trend for a year, or several years, or decades, or centuries, I suppose. What the trend line implies is that the probability of that happening diminishes as the future period of levitating prices is extended. In other words, don’t bet on it lasting as long as you want it to. Same would apply if prices were below trend.