Summary of the U.S. Census Bureau s 2016 County-Level Population and Component Estimates for Massachusetts Prepared by: UMass Donahue Institute Economic and Public Policy Research Population Estimates Program For Release: March 23, 2017 On March 23, 2017, the U.S. Census Bureau released population estimates for July 1, 2010 through July 1, 2016 for Massachusetts and U.S. counties. These estimates are based on the demographic components of change since Census 2010, including births and deaths, domestic and international migration, and the group quarters population for each county. To go directly to the U.S. Census estimates page, go to: https://www.census.gov/programs-surveys/popest/data/data-sets.html. 1
County Population Change: Single-Year Change 2015-2016 Figure 2 According to the new county-level population estimates released by the U.S. Census Bureau, the greatest numerical increases in Massachusetts from July 1, 2015 to July 1, 2016 were seen in Middlesex County at 8,737 persons gained; Suffolk County at 7,542; and Plymouth County at 3,685. In terms of percentage change, the largest gains were in Nantucket County at 1.4%, Suffolk County at 1.0%, and Plymouth County at 0.7%. These rankings are comparable to growth patterns in other recent estimates series produced by the U.S Census Bureau. Middlesex and Suffolk were also top population gainers last year while Suffolk and Nantucket were among the three counties with the greatest percentage increase last year. Plymouth County moved up in rank this year, now replacing Essex County as the third fastest growing county in the state by single-year percentage growth. The greatest population decreases over the 2015-2016 period were estimated in Berkshire County at -768; Hampden County at -611; and Barnstable County at -345. The most significant percentage point decreases from July 2015 to July 2016 were in Berkshire County at -0.6%, Franklin County at -0.2%, and Barnstable County at -0.2%. 2
Table 1 below shows county population estimates, change, and rankings for the July 1, 2015 and July 1, 2016 estimates years. Table 1. Annual Estimates of Resident Population Change and Rankings for Massachusetts Counties Geography July 1, 2015 to July 1, 2016 July 1 Population Estimate Change 2015 to 2016 Rank Change 2015 to 2016 2015 2016 Number Percent Number Percent Massachusetts 6,784,240 6,811,779 27,539 0.4% (X) (X) Barnstable 214,621 214,276 (345) -0.2% 12 12 Berkshire 127,671 126,903 (768) -0.6% 14 14 Bristol 556,967 558,324 1,357 0.2% 7 8 Dukes 17,217 17,246 29 0.2% 10 10 Essex 776,111 779,018 2,907 0.4% 4 6 Franklin 70,550 70,382 (168) -0.2% 11 13 Hampden 469,078 468,467 (611) -0.1% 13 11 Hampshire 161,049 161,816 767 0.5% 8 5 Middlesex 1,581,037 1,589,774 8,737 0.6% 1 4 Nantucket 10,858 11,008 150 1.4% 9 1 Norfolk 694,895 697,181 2,286 0.3% 5 7 Plymouth 509,880 513,565 3,685 0.7% 3 3 Suffolk 776,688 784,230 7,542 1.0% 2 2 Worcester 817,618 819,589 1,971 0.2% 6 9 UMass Donahue Institute. Source: Annual Estimates of the Resident Population: April 1, 2010 to July 1, 2016 (PEP_2016_PEPANNRES), U.S. Census Bureau, Population Division, March 23, 2017. Suffolk and Middlesex Counties had, by far, the highest rates of international migration in the state in 2016, which helped to boost their population growth over the past year, while Nantucket, Suffolk, and Middlesex counties had the highest rates of natural increase from 2015 to 2016, meaning they had high rates of births compared to deaths over the past year as compared to other parts of the state. Plymouth County increased its population through a combination of relatively strong domestic migration and modest international migration and natural increase. See the components section of this summary for details. Among the counties that lost population in the past year, Barnstable Berkshire, and Franklin Counties all experienced a greater number of deaths than births in the 2015 to 2016 period. Berkshire and Franklin counties also experienced a net loss of domestic migrants that was not fully offset by positive net international immigration in the 2015 to 2016 period - as did Hampden County - which contributed to population loss in those areas. 3
County Population Change: Cumulative Change 2010-2016 Figure 3 While single-year change refers to estimated growth or decline between July 1 of one estimates year to July 1 of the next, cumulative change measures the total net change since the last Census count date of April 1, 2010. Table 2, below, shows county population estimates, cumulative change, and rankings from the April 1, 2010 base to the July 1, 2016 estimate, while the map above (Figure 3) map displays the cumulative percentage change for each county from Census 2010 to the July 1, 2016 estimate. According to these estimates, Suffolk County has been growing the fastest, in terms of percentage growth, since the last Census at 8.6%, followed by Nantucket at 8.2% and Middlesex at 5.8%. In numeric terms, Middlesex County led the state, growing by 86,717 persons since 2010, followed by Suffolk at 62,151 and Essex at 35,847. 4
Table 2. Cumulative Estimates of Resident Population Change and Rankings for Massachusetts Counties Geography April 1, 2010 Estimates Base April 1, 2010 to July 1, 2016 Population Estimates Change, 2010 to 2016 Rank Change July 1, 2016 Number Percent By Number By Percent Massachusetts 6,547,813 6,811,779 263,966 4.0% (X) (X) Barnstable 215,868 214,276 (1,592) -0.7% 13 12 Berkshire 131,272 126,903 (4,369) -3.3% 14 14 Bristol 548,260 558,324 10,064 1.8% 7 10 Dukes 16,535 17,246 711 4.3% 11 5 Essex 743,171 779,018 35,847 4.8% 3 4 Franklin 71,372 70,382 (990) -1.4% 12 13 Hampden 463,625 468,467 4,842 1.0% 8 11 Hampshire 158,080 161,816 3,736 2.4% 9 9 Middlesex 1,503,057 1,589,774 86,717 5.8% 1 3 Nantucket 10,172 11,008 836 8.2% 10 2 Norfolk 670,985 697,181 26,196 3.9% 4 6 Plymouth 494,949 513,565 18,616 3.8% 6 7 Suffolk 722,079 784,230 62,151 8.6% 2 1 Worcester 798,388 819,589 21,201 2.7% 5 8 UMass Donahue Institute. Source: Annual Estimates of the Resident Population: April 1, 2010 to July 1, 2016 (PEP_2016_PEPANNRES), U.S. Census Bureau, Population Division, March 23, 2017. Components of Change As described earlier, county-level estimates are produced by the U.S. Census Bureau using the latest data available for the various components of change, which include births and deaths, domestic migration (within the United States) and international migration, and the group quarters population for each county. The following section describes changes in the Massachusetts county-level population estimates due to births, deaths, and migration. Natural Increase Natural increase is the net change in population after births and deaths are added together. The following chart (Figure 4) shows the estimated number of births, deaths, and the resulting net natural increase in each county for the period of July 1, 2015 to July 1, 2016. Note that in counties with a high number of births compared to deaths, such as Middlesex and Suffolk, we see a positive net natural increase and stronger population growth. In counties where the number of deaths outweighs the number of births, such as Barnstable and Berkshire, we see negative values for net natural increase. 5
Figure 4 UMass Donahue Institute. Source: Estimates of the Components of Resident Population Change: April 1, 2010 to July 1, 2016 (PEP_2016_PEPTCOMP), U.S. Census Bureau, Population Division, March 23, 2017. Migration In the estimates process, net international migration measures in- and out-migration between a county and places outside the U.S. These numbers represent estimates produced by the U.S. Census Bureau s analysis of American Community Survey data on the foreign-born population and other data sources. Domestic migration, sometimes called internal migration, measures movement from one county to another within the U.S. To estimate this component, the U.S. Census Bureau uses a combination of IRS data on tax filers and Medicare enrollment data. The sum of these two types of migration, international and domestic, equals the total net migration. The following chart shows, the international, domestic, and total net migration estimates for each Massachusetts county for the period of July 1, 2015 to July 1, 2016. Note that most Massachusetts counties 10 out of 14 show negative domestic migration, meaning populations have moved from these counties to other counties within the U.S. However, in all counties except Berkshire, Franklin, and Hampden, the negative domestic migration is offset by greater international immigration sometimes to an enormous degree, as seen in Essex, Middlesex, and Suffolk Counties in the chart below (Figure 5). 6
Figure 5 UMass Donahue Institute. Source: Estimates of the Components of Resident Population Change: April 1, 2010 to July 1, 2016 (PEP_2016_PEPTCOMP), U.S. Census Bureau, Population Division, March 23, 2017. Components of Change Estimates As described above, component data on births, deaths, domestic migration, and international migration combine together (along with group quarters updates and a residual component) to factor into population change for each county. The following tables outline the numerical change in each of these components for each county. Table 3 shows single-year change from July 1, 2015 to July 1, 2016, while Table 4 shows the cumulative change from the April 1, 2010 Census base to July 1, 2016. 7
Table 3. Annual Estimates of the Components of Population Change: July 1, 2015 to July 1, 2016 Total Vital Events Net Migration Massachusetts Population Natural International County Births Deaths Total Domestic Change [1] Increase [2] Barnstable (345) (1,402) 1,506 2,908 1,136 391 745 Berkshire (768) (421) 1,046 1,467 (230) 258 (488) Bristol 1,357 427 5,625 5,198 1,156 1,295 (139) Dukes 29 14 152 138 8 0 8 Essex 2,907 1,684 8,518 6,834 1,554 4,501 (2,947) Franklin (168) (95) 589 684 (38) 177 (215) Hampden (611) 778 5,204 4,426 (1,308) 3,048 (4,356) Hampshire 767 (183) 1,056 1,239 947 838 109 Middlesex 8,737 5,865 17,592 11,727 3,347 12,192 (8,845) Nantucket 150 90 143 53 62 63 (1) Norfolk 2,286 1,332 7,278 5,946 1,449 3,437 (1,988) Plymouth 3,685 613 5,216 4,603 3,064 1,464 1,600 Suffolk 7,542 4,318 9,470 5,152 3,184 9,498 (6,314) Worcester 1,971 1,441 8,629 7,188 961 3,736 (2,775) Table 4. Cumulative Estimates of the Components of Population Change: April 1, 2010 to July 1, 2016 Total Vital Events Net Migration Massachusetts Population Natural International County Births Deaths Total Domestic Change [1] Increase [2] Barnstable (1,592) (8,019) 9,771 17,790 6,338 2,310 4,028 Berkshire (4,369) (2,166) 6,891 9,057 (1,956) 1,419 (3,375) Bristol 10,064 3,856 35,559 31,703 6,970 7,194 (224) Dukes 711 142 993 851 580 12 568 Essex 35,847 12,772 52,950 40,178 23,937 25,723 (1,786) Franklin (990) (371) 3,852 4,223 (391) 981 (1,372) Hampden 4,842 6,191 33,308 27,117 (409) 17,549 (17,958) Hampshire 3,736 (777) 6,833 7,610 4,406 4,765 (359) Middlesex 86,717 40,882 110,042 69,160 49,224 70,952 (21,728) Nantucket 836 506 879 373 325 352 (27) Norfolk 26,196 10,054 45,297 35,243 17,515 19,764 (2,249) Plymouth 18,616 5,195 32,141 26,946 13,120 8,495 4,625 Suffolk 62,151 29,925 59,313 29,388 33,648 54,926 (21,278) Worcester 21,201 11,969 54,291 42,322 10,176 21,646 (11,470) (X) Not applicable. [1] Total population change includes a residual. This residual represents the change in population that cannot be attributed to any specific demographic component. See Population Estimates Terms and Definitions at http://www.census.gov/popest/about/terms.html. [2] Net international migration (except for Puerto Rico) includes the international migration of both native and foreign-born populations. For population estimates methodology statements, see http://www.census.gov/popest/methodology/index.html. UMass Donahue Institute. Source data: U.S. Census Bureau CO-EST2016_ALLDATA. Release date: March 23, 2017 Below are tables displaying these same components of change as average rates per 1,000 persons. These rates are useful when comparing one county to another. Table 5 includes rates for component changes over one year from July 1, 2015 through July 1, 2016, while Table 6 shows average rates over the six-year period from the April 1, 2010 Census through July 1, 2016. 8
Table 5. Estimated Annual Rates* of the Components of Population Change for Single Year July 1, 2015 to July 1, 2016 Vital Events Net Migration Massachusetts Total Population Natural International County Change [1] Births Deaths Total Domestic Increase [2] Barnstable (1.2) (6.5) 7.0 13.6 5.3 1.8 3.5 Berkshire (5.1) (3.3) 8.2 11.5 (1.8) 2.0 (3.8) Bristol 2.8 0.8 10.1 9.3 2.1 2.3 (0.2) Dukes 1.3 0.8 8.8 8.0 0.5 0.0 0.5 Essex 4.2 2.2 11.0 8.8 2.0 5.8 (3.8) Franklin (1.9) (1.3) 8.4 9.7 (0.5) 2.5 (3.1) Hampden (1.1) 1.7 11.1 9.4 (2.8) 6.5 (9.3) Hampshire 4.7 (1.1) 6.5 7.7 5.9 5.2 0.7 Middlesex 5.8 3.7 11.1 7.4 2.1 7.7 (5.6) Nantucket 13.9 8.2 13.1 4.8 5.7 5.8 (0.1) Norfolk 4.0 1.9 10.5 8.5 2.1 4.9 (2.9) Plymouth 7.2 1.2 10.2 9.0 6.0 2.9 3.1 Suffolk 9.6 5.5 12.1 6.6 4.1 12.2 (8.1) Worcester 2.9 1.8 10.5 8.8 1.2 4.6 (3.4) *Rates per 1,000 average population. UMass Donahue Institute. Source data: U.S. Census Bureau CO-EST2016_ALLDATA. Release date: March 23, 2017 Table 6. Average Estimated Rates* of the Components of Population Change for April 1, 2010 to July 1, 2016 Period Vital Events Net Migration Massachusetts Total Population Natural International County Change [1] Births Deaths Total Domestic Increase [2] Barnstable (1.3) (6.0) 7.2 13.2 4.7 1.7 3.0 Berkshire (5.3) (2.8) 8.5 11.3 (2.6) 1.8 (4.4) Bristol 3.0 1.0 10.3 9.2 1.9 2.1 (0.2) Dukes 6.9 1.2 9.3 8.2 5.7 0.1 5.6 Essex 7.5 2.6 11.1 8.5 4.9 5.4 (0.6) Franklin (1.7) (0.9) 8.7 9.6 (0.8) 2.2 (3.0) Hampden 1.9 2.1 11.4 9.3 (0.3) 6.1 (6.3) Hampshire 2.6 (0.8) 6.8 7.6 3.4 4.8 (1.3) Middlesex 9.2 4.2 11.3 7.1 5.1 7.4 (2.3) Nantucket 13.2 7.4 13.2 5.8 5.8 5.4 0.4 Norfolk 6.2 2.3 10.5 8.2 3.9 4.6 (0.7) Plymouth 5.7 1.6 10.2 8.6 4.1 2.7 1.4 Suffolk 13.3 6.3 12.6 6.2 7.0 11.7 (4.7) Worcester 4.2 2.3 10.7 8.4 1.9 4.3 (2.4) *Rates per 1,000 average population. (X) Not applicable. [1] Total population change includes a residual. This residual represents the change in population that cannot be attributed to any specific demographic component. See Population Estimates Terms and Definitions at http://www.census.gov/popest/about/terms.html. [2] Net international migration (except for Puerto Rico) includes the international migration of both native and foreign-born populations. For population estimates methodology statements, see http://www.census.gov/popest/methodology/index.html. UMass Donahue Institute. Source data: U.S. Census Bureau CO-EST2016_ALLDATA. Release date: March 23, 2017 For more information on the U.S. Census Bureau s Vintage 2016 Population Estimates Release and to see national county data, see: https://www.census.gov/programs-surveys/popest/data/data-sets.html. 9
To see additional summary reports by the UMDI Population Estimates Program on U.S. Census Bureau estimates releases for Massachusetts, follow this link: http://www.massbenchmarks.org/statedata/news.html 10