California has long been known for, and even defined by, its tremendous population growth. In 2019, the state reached another demographic milestone, becoming the first state with 40 million residents. (Texas, the state with the second-largest population, has not yet reached 30 million.) Equally remarkable is California’s diversity: its population includes large groups of immigrants from more than 60 countries, and no single race or ethnic group constitutes a majority. The rate of growth has slowed in recent decades, but the number of people added to the state’s population has been substan­tial—300,000 each year, on average, from 2010 through 2019.

California has invested significantly in preparations for the 2020 decennial census. An accurate count is crucial, as the census is used to allocate billions in federal funding and determine the number of congressional districts in each state. The state, local governments, community organizations, and other stakeholders are making extra efforts to ensure that all Californians are counted. California has long had disproportionate shares of populations that are difficult to count, including young adults, renters, and immigrants. The challenge is particularly acute this year. Not only has the 2020 Census been underfunded by the federal government, but federal rhetoric and actions on border security, deportation, and immigrant rights could dampen participation. PPIC research shows that a poor count would cost California a seat in the House of Representatives; with an accurate count, the state might gain a seat.

Population projections suggest that California will gain millions of new residents in each of the next two decades. These gains will support a growing economy and require new incentives to improve infrastructure and public services—including education, transportation, housing, water, and health care.

This publication is part of a briefing kit that highlights our state’s most pressing long-term policy challenges in 11 key areas: