I grew up in Colorado, and complaints about housing costs and traffic increases due to the influx of Californians has been a constant since the 1970s. At least.
I'm going posit that it's perception more than any actual changes due to fleeing 'fornians.
Could be, but one hears of a multiplying effect: numbers of households moving from California times the absolute housing price differences, in terms of money flowing into local housing markets.
I'm going posit that it's perception more than any actual changes due to fleeing 'fornians.