Single family home in California (Credit: IRA)

Nearly half of U.S. states aren’t producing enough housing to keep up with growing demand and California is the biggest culprit, according to one measure of production over the last 15 years.

A report by consulting firm ECONorthwest found California is short by 3.4 million units, accounting for more than half the 7.3-million-unit shortage nationwide, the Wall Street Journal reported. Nevada, Arizona, and Massachusetts also have significant shortages.

The research was financed by a group that advocates loosening building code restrictions, which includes some developers who would benefit from those less restrictive laws. The group includes Palo Alto-based Essex Property Trust, Washington-based Holland…