 likely take up a big old chunk. That's reflected in the Consumer Price Index. They're about a third of the whole CPI. Steve Reed is an economist with the Bureau of Labor Statistics, which puts out the CPI. One reason shelter inflation has stayed persistently high in the past couple of years, says Jessica Lautz, an economist with the National Association of Realtors, is that a lot of young adults want their own space. There are a lot of people who don't want to double up anymore.