Random Samplings

Census Data Mapper: Beta Version Now Available

Posted on January 22, 2013 by jennifer

Written by: Stephen F. Jones

Are you interested in creating maps that display 2010 Census Population and Housing data for use in reports, presentations, or general viewing? If so, then the Census Data Mapper is an application you should explore. The beta version of the application is now available for use at the following URL: http://www.census.gov/geo/maps-data/maps/datamapper.html.

This web mapping application provides users with a simple interface to view, customize, save and print thematic maps of the United States, using data from the 2010 Census. The beta version contains a set of 2010 Census data relating to age and sex, population and race, and family and housing in the United States by county or equivalent entity. The map design and layout were created by Census Bureau cartographers and are similar to that used on standard Census Bureau map products.

Software Functionality

Users can customize the map display by choosing the number of data classes, selecting from a series of predefined fill colors, and selecting the type of data classification.

The interface also allows users to explore the data sets by viewing information on the map and in tabular form. Selecting a geographic unit on the map will result in the corresponding value in the data table being highlighted and vice versa.

Maps created within the application can be saved to your computer in PDF format and subsequently viewed and printed through Adobe Acrobat Reader. The PDF will be a finished map product containing only the map image, and not the other graphics from the web page, and suitable for use in presentations and reports.

Future Plans

The current beta version of the software contains just over 20 data items from the 2010 Census, but future versions will include many more and may also include other data sets. Future versions may also include data and maps for different levels of census geography.

For future software releases, we are exploring new ways to improve the quality of the map and reduce file size.

The Census Bureau is interested in getting feedback from users on the usefulness of the application and desired future enhancements. We hope you will provide us with your comments, suggestions, and future needs so we can improve the product in future releases. Please email responses and feedback to geo.geography@census.gov.

Posted in Geography, Uncategorized | Leave a comment

What a Difference Four Years Make: U.S. Population Projected to Grow at a Slower Pace Over the Next Five Decades

Posted on December 12, 2012 by jennifer

The U.S. population is projected to grow at a slower pace over the coming years than was projected four years ago, according to new population projections released today. So, how much is the U.S. population expected to grow over the next several decades? Moreover, how and why has the projected growth rate of the population changed between the 2008 and 2012 series?

What difference does four years make? The population projections are based on assumptions about the future levels of fertility, mortality, and international migration that are based on past trends. The new series of projections incorporates data that are more recent on births, deaths, and net international migration. Fertility and international migration have declined in recent years. The annual number of births in the United States has been declining since 2008, while the number of net international migrants began to decline after 2001. Growth of the population is contingent on births, deaths, and migration. Declines in births and migration reduce the population’s growth rate, while decreases in deaths increase population size.

According to the 2012 National Projections, the U.S. population is projected to be around 399.8 million in 2050. In the 2008 series, the population was projected to be around 439.0 million. The new series projects 39.2 million fewer people living in the United States in 2050 than the 2008 series (Figure 1).

What is driving this difference? The most important driver is international migration (Figure 2). The 2012 series projects 41.2 million net number of international migrants, while the series released in 2008 projected 65.6 million net migrants – a difference of 24.4 million. The next largest driver of this difference is the projection of births. The 2008 series projected 193.2 million births to occur between 2012 and 2050. The 2012 series projects fewer births, just over 175 million for the 38-year period. The total number of projected deaths was also lower in the 2012 series, which projected 128.4 million compared to the 133.1 million deaths projected in the 2008 series (a difference of 4.6 million). Finally, the 2012 National Projections are based on a smaller population in 2011 than what was projected in the 2008 series. In 2011, the Census Bureau estimated there were 311.6 million people living in the United States. This estimate is 1.6 million lower than the projected population in 2011 from the 2008 National Projections.

When we add up the numbers, 24.4 million fewer migrants plus 17.8 million fewer births minus 4.6 million fewer deaths plus 1.6 million difference in the estimates of the population for the population in 2011, we arrive at the total difference of 39.2 million.

More information about the Census Bureau’s population projections, including the new series of tables with results from the 2012 National Projections, is available at: http://www.census.gov/population/projections/.

Posted in Population | Tagged migration, population | 2 Comments

Forgoing Alchemy, Tarot Cards, and Crystal Balls: Demographers Use Empirical Data to See How the Future Will Unfold

Posted on December 11, 2012 by jennifer

How Does the Census Bureau Measure the Future Population?

Written by: Jennifer M. Ortman

Have you ever wondered how the Census Bureau projects the future population of the United States? We start with a few basic questions: How many people currently reside in the United States? How many births will there be? How many people will die? How many people will move to the United States? How many people will move out of the United States? The answers to these questions are the basis of our population projections. Once we answer these questions, calculating the future population is simple. We just add the number of births and people who move in to the current population, subtract the number of deaths and those who leave, and see how the demographic future unfolds!

Looking at the Details

The Census Bureau projects the size and characteristics (age, sex, race, and Hispanic origin) of the future population using the most current estimates of the U.S. population. Projections are produced for future years one year at a time based on the components of population change – births, deaths, and international migrants. Assumptions about the future number of births, deaths, and international migrants are based on past trends in these components.

To project deaths, we look at death rates, that is, the number of deaths per thousand population by age. Since these rates have been falling in recent years, we examine recent trends and assume that similar trends will continue into the future. We must decide, for example, to what extent recent reductions in old age mortality will continue. Similarly, for births, we look at fertility rates, that is, the number of births per women in the childbearing ages. Rates have been falling in recent years. Will these downward trends continue? We try to find a balance between these recent trends and what are likely to be the longer-term trends.

International migration is projected as the difference between the number of immigrants who come to the United States and the number of emigrants who leave from the United States each year. Levels of international migration over the past several decades are evaluated to determine how many migrants can be expected to come in the future. The level of international migration increased steadily during the 1980s and 1990s, reaching an annual peak of 1.2 million in 2001. Over the course of the first decade of the 2000s, the number of net international migrants decreased, reaching a level around 725,000 in 2011. We must decide whether more recent short-term declines in international migration will persist into the future, or if the levels of net international migration will ultimately continue to increase following the longer-term trends. Again, we try to find a balance between these recent trends and the longer-term trends.

Once assumptions about fertility, mortality, and international migration have been made, we can produce the population projections. For each projected year, we begin with the population for the previous year and age that population forward one year, so that newborns are now 1 year old, 1 year olds are now 2, etc. Next, we calculate the number of births by applying the projected fertility rates to the female population in that year. We then add the projected number of births and immigrants to the population at the beginning of that year. Deaths for that year are calculated by applying the projected mortality rates to the population in that year. The projected number of deaths and emigrants are then subtracted from the population. The result is the projected population for the next year. This process is repeated for each year of the projection series, by sex, race, and Hispanic origin, typically for a total of 50 years. Through repeating this process, we see how the future will unfold from a demographer’s perspective.

The Census Bureau’s population projections are used by researchers, policymakers, businesses, and other government agencies for a variety of purposes. A topic of great interest is the aging of the population. Projections of the old-age population are of particular interest for those assessing government programs such as Medicare and Social Security. Projections of the working-age population, typically between the ages of 20 and 64, are of interest to businesses and service providers attempting to evaluate future demand for their products and services as well as the means of supplying those goods. Projections of births and the population under the age of 18 are of interest to educators tasked with planning for future demands on the education system.

For Further Information

For more information about the Census Bureau’s population projections, including the methodology used to produce our most recent projections and results, please visit: http://www.census.gov/population/projections/.

Posted in Population | Tagged migration, population, projections | Leave a comment

America: A Nation on the Move

Posted on December 10, 2012 by jennifer

Written by: Alison Fields and Robert Kominski

Have you moved in the last five years? Earlier today, the Census Bureau released a collection of data on rates of migration, or “geographic mobility.” Between 2011 and 2012, 12 percent of people in the country over age 1 moved at least once. This showed that the rate of yearly migration increased, compared with the previous year’s all-time low of 11.6 percent.

The population of the United States is considered highly mobile. Each year, people move from their place of birth or current residence to live somewhere else in their city, county, state or the nation. When and where people move has a huge impact on the local demographics and economies of the places where they used to live and where they live now.

Knowing the number and some details about movers in and out of a place is part of information on the population that helps the federal government plan for emergency services following natural disasters. State and local planners use migration data for population forecasting and deciding where to put new hospitals, libraries and public schools. Private businesses use it to plan for opening new offices and stores for jobs and commerce.

Generally, we measure migration by asking someone if she was living at her current address at some specific point in the past, such as last year, last month or April 1, 2000. Many of our surveys use the period of one year, which is the case with annual data collected as part of the American Community Survey (ACS) and the question in the Current Population Survey, Annual Social and Economic Supplement (CPS). Some of the products released this week use data from these surveys but look at a longer period – asking, “Where did you live five years ago?”

The five-year question first appeared in 1940 as part of the long-form decennial census data collection. It provided migration data that could be cross-tabulated by a large assortment of social, demographic and economic characteristics, and for relatively small pieces of geography. Along with other questions added to the census that year, it helped measure the effects of the Great Depression. A five-year migration question was added to the CPS in 1975 to help provide an idea of patterns of movement for the beginning part of each decade. It now appears in the CPS data collection every five years.

With the implementation of more routine surveys such as the CPS, it became possible to measure migration more frequently, and in 1948, we added the one-year migration question to the March CPS. With the transition of decennial long-form data collection to the ACS in 2005, an annual migration question was added to that survey to take advantage of its larger sample and greater geographic precision. Even shorter-duration data has been collected as part of the Survey of Income and Program Participation (SIPP), where we can identify moves down to the specific month.

Most of the information released today comes from the CPS. We can look back to 1948 and see the number of movers in the United States and the rate at which people are moving.

Although the rate people move reached an all-time low in 2011 and is now increasing, that does not tell us about the volume of the flow. This graph shows that even when the mover rate is low, there are many Americans moving. This movement affects change across the country. The ACS data released today on state-to-state migration flows is how we know where in the country to see the impact of the change, or where people are moving.

We also observe that the longer the period we ask about in the mover question, the greater the likelihood that someone will tell us that he experienced a move. For example, the CPS 2010 one-year rate of migration reported is 12.5 percent, while the 2010 five-year rate from CPS is 35 percent. Alternatively, 35 percent of people responded that they moved at least once in the last five years, but only 12.5 percent said the same for the previous one year.

Each of these sources provides different and valuable complementary data about the migration process, but because of a variety of operational and definitional contexts, also will not provide exactly comparable data or estimates. No one data collection effort provides the answer to every possible question, so we use multiple data opportunities to provide a fuller and more detailed picture of the issue. Collectively, the different information from these statistical products paints a more vivid picture of our nation’s movers.

More detail about the trends in domestic migration in the United States is available in the new set of products released today on the Geographic Mobility Page.

Read the Press Release

Posted in Housing | Tagged Current Population Survey, geography, migration | 1 Comment

Easy Exploration into Your Community’s Statistics

Posted on December 7, 2012 by jennifer

Easy Stats: Your Source for Easy-to-Use Data, At Your Fingertips

Written By: Nancy Potok

Yesterday we released Easy Stats, one of the latest web technology tools developed by the U.S. Census Bureau to make our data quicker and easier to access. As its name suggests, Easy Stats provides a user-friendly way to retrieve timely statistics about our nation’s people, places and economy.

The Census Bureau is adding exciting new ways to deliver our data to you, making data more accessible in order to help you make informed decisions in your everyday life. Along with Easy Stats, our website transformation, our newly released mobile application, America’s Economy, and our API, we are transforming the way we deliver data to the public.

Through customer research and feedback, we realized that our visitors to census.gov shouldn’t have to work so hard to find the information and statistics they’re looking for to complete their research, personal projects or business needs. Since then, we’ve been working hard to revamp access to the nation’s crucial statistics.

This easy-to-use portal provides quick access to the wealth of statistics collected by the Census Bureau through the American Community Survey or ACS. Through the innovation of the ACS, every community, every year, receives detailed statistics about its social, economic and housing characteristics. The Census Bureau is the only source of statistics at the local level every year that are consistent across the entire nation, giving even the smallest communities timely information essential for decision-making.

Because this information is so important, I’m delighted that Easy Stats now provides access in three simple steps. All you have to do is choose a topic, select your geography and hit display data. You also will have options to show various breakdowns by race, age, gender, veteran status and various geographic localities. This new interactive tool allows you to view the latest American Community Survey tables; search by geography down to the local level (including incorporated places, like cities and towns, and census designated places); view detailed racial, age and gender breakdowns; and compare communities.

In addition to counting on the Census Bureau for data accuracy and data integrity, Easy Stats enables you to count on the Census Bureau for increasing access to our important statistics.

Whether you are a local business owner writing a loan proposal, a city planner looking ahead to the future or you’re just simply writing a report or exploring your community, Easy Stats will be able to assist.

The Census Bureau is bringing data directly to your fingertips, and we invite you to discover your community today with Easy Stats.

While we continue these innovative and user-focused improvements, we hope you’ll provide feedback and share with us how you use these products to help you find the data you need. We’ve made it even easier to share feedback online and via email at cnmp.web.comments.list@census.gov.

Stay tuned in the coming weeks for an update on our next mobile app, “Dwellr,” which will provide another way of putting American Community Survey statistics at your fingertips.

You can also follow us on Facebook and Twitter @uscensusbureau for the latest updates, news and statistics about our changing nation’s people, places and economy.