The Treasure Valley is growing quickly in myriad ways, and with that has come a massive leap in the gap between the Boise metropolitan area's richest and poorest households, according to a Bloomberg analysis of Census Bureau data.
The business news site analyzed average income among the top and bottom 20 percent of households. It found that the wealth gap in the Boise area widened by $44,400 from 2011 to 2016. That is so much that it rocketed Boise from No. 76 on Bloomberg's ranking of disparities in the top 100 metro areas to No. 7.
The No. 76 ranking one year ago was based on 2010-2015 data.
The new data could be because of West Coast residents moving into the Boise area's more-affordable housing market. Bloomberg said federal data show that California led all states in migration inflows into Idaho in the past three years.
According to Bloomberg, the average income for Boise-area households in the top 20 percent was $125,600 in 2011. By 2016, that had risen to $182,000. Meanwhile, the Valley's poorest households have "stagnated around $12,000," Bloomberg reported, for a whopping $170,000 difference.
Nationally, the average gap rose by $31,000 to about $197,000, Bloomberg found.
The gap between the Valley's super-rich and middle-class residents widened, too.
Bloomberg looked at the difference between average income for the top 5 percent of households and the middle 20 percent.
Nationally, the gap in those populations widened by $59,000 between 2011 and 2016. In the Boise area, it grew from $175,100 to $279,400, a difference of $104,300. That landed the Boise area in the No. 5 slot on Bloomberg's list of places where the gap had widened most.
The wealth-gap rankings compare data from standard metropolitan statistical areas. The Boise SMSA includes Ada, Canyon, Boise, Gem and Owyhee counties.