Population Trends

Size and Growth

Missouri has slipped to the nation's seventeenth most populous state as a result of lower than average growth. Missouri's rank among the nation's most populous states has been on the decline since the turn of the century, when Missouri ranked the fifth most populous. Missouri's standing fell two positions during the decade of the 1990s dropping from the fifteenth spot in 1990 to seventeenth by 2000.

Projections indicate that Missouri's growth will slow in the coming decades. Overall growth between 2000 and 2030 will average roughly six percent per decade. Census Bureau models predict the nation to grow at about ten percent per decade. Missouri's projected rate of growth through the year 2030 will be less than was seen during the 1960s, 70s and 90s but greater than the 1930s, 40s and 80s. The model projects Missouri's population to grow by roughly 1.2 million people over the next thirty years, a 21percent increase, for a total population approaching 6.8 million people in 2030.

Components of Change

Unlike Sunbelt states where net in-migration is the primary cause of population increase, Missouri's increases are mainly due to natural increase (births minus deaths). From 1930 to 2000, natural growth averaged about 287 thousand people per decade. This growth was offset by a net out-migration of about six thousand people per decade. However, Missouri experienced an in-migration of almost 260 thousand people during the 1990s. Favoring more recent migration trends, the population projection model predicts a natural increase of approximately 732 thousand people between 2000 and 2030, and net in-migration of nearly 420 thousand people.


For most of the last century, fertility has been the primary cause of Missouri's population increase. Therefore, it is important to consider the dramatic swings in fertility that have occurred in Missouri's past.

The total fertility rate is a measure of the average number of births women would have if a set of age-specific birth rates for a given year were applied throughout their reproductive years. Total fertility dropped throughout the 19th Century, into the early 20th Century, and through the years of the Great Depression. The rate reached a low of 1.99 children per woman in 1935. Annual births averaged fewer than 60 thousand in Missouri in the late 1930s.

The trend reversed after World War II. The baby-boom era, which lasted from 1946 to 1964, saw the number of annual births rise to nearly 100 thousand children. At its peak in 1960, the total fertility rate rose to an average of 3.63 children per woman, the highest rate this century.

The fertility rate then reversed again during the baby-bust or "Generation X" era, which lasted from 1965 to the late 1970s. At its low point in 1976, just 16 years after the baby-boom peak, the total fertility rate dropped to an average of 1.75 children per woman, the lowest rate this century. Annual births fell below 70 thousand during this time.

Another minor reversal, the "baby-boomlet," began in the late 1970s. Births and the fertility rate rose. By 1990, annual births had increased to nearly 80 thousand, while the total fertility rate edged up to 2.00. However, rising births were due more to the large number of women in the childbearing age group (primarily baby-boomers) than to rising fertility. The total fertility rate remained at 2.00 and annual births averaged roughly 75 thousand for the decade of the 1990s.

The projections are based on the assumption that future fertility rates will remain at the year 2000 levels. Annual births are projected to increase from an average of 76 thousand in the period 2000-2005 to an average of 82 thousand in the period 2025-2030. The increase is the result of an increasing number of women in the childbearing years through the 2025 projection cycle.


Increasing longevity has kept the number of deaths each year in Missouri at about the same level over the past half century despite a growing population. Life expectancy at birth rose from 53 years in 1910 to 68 years in 1950 to 76 years in 2000. Continued improvements in maternal health care, general health habits, and treatment of heart disease should cause overall longevity to rise even higher, although recent trends suggest that some young adult populations may experience only minor gains or even decline.

If moderate assumptions about mortality hold, women will continue to outlive men by several years, but the gap will narrow. In 2000, life expectancies at birth in Missouri were 73 years for males and 79 years for females.

The number of resident deaths in Missouri has averaged near 50 thousand per year since the early 1960s. However, deaths are expected to increase due to the aging baby-boomers. Deaths are projected to increase from a yearly average of 54 thousand in the 2000-2005 period to 59 thousand in the period of 2025-2030.


For most of the last century, natural growth in Missouri has been offset by small net out-migration. However, the state has experienced periods of in-migration during the 1960s, 70s and again in the 90s. The migration gains of the 1960s and 70s averaged only a few thousand people while net immigration during the 1990s hit almost 260 thousand persons.

The projection model carries migration trends over the period 2000-2007 forward to 2030. Because of constraints built into the model, projected net inflow will peak at 82 thousand in-migrants during the 2005-2010 period and slow to 54 thousand in-migrants from 2025 to 2030.

Age Distribution

Historic swings in fertility continue to transform the age profile of Missouri's population. Figure 1 graphically represents Missouri's population distribution for 1900, 1950, 2000, and 2030 by age and gender.

Figure 1: Missouri Population Pyramids

Missouri's population distribution in 1900 was similar to those of many developing countries today. The distribution was wide at the base for young age groups and progressively narrowed toward the top as higher mortality claimed increasing numbers of persons in older age groups.

By 1950, however, the population distribution had begun to lose its pyramidal shape. At the base of the graph are wide bands representing the large post-war birth cohorts (the baby-boom). Just above the wide base are narrow bands representing the smaller number of persons born during the Great Depression.

In 2000, the baby-boom is conspicuous in the middle age groupings. Below this are narrow bands which represent the "baby-bust" under which lie the "boom-echo" (the "boomers" children) visible as a swelling in the 5-to 19-year-old age groupings.

As projected, Missouri's population will have a rectangular cast by 2030. Baby-boomers will swell upper sections of the pyramid to unprecedented widths and long-sustained low levels of fertility will produce consistent narrow bands in the lower half of the age distribution.

The discussion below underscores major changes in Missouri's age distribution for select groups between 1950 and 2000 and highlights changes projected to occur between 2000 and 2030.

Preschool Age

The size of the under-five age group shrank from just under ten percent of the state's total population in 1950 to seven percent by 2000. In numeric terms, the group dropped from 384 thousand to 370 thousand, or four percent. In 2030 it is projected this age group will have increased by 13 percent, or 47 thousand additional preschoolers. However, due to larger increases in Missouri's older age groupings, preschoolers are expected to represent only six percent of the population by 2030.

Elementary School Age

The 5-13 age group increased by 183 thousand children between 1950 and 2000, a 33 percent increase, for a final population of 729 thousand. However, the group fell from 14 to 13 percent of the total population between 1950 and 2000. This age group is projected to increase an additional 39 thousand persons, or five percent, by 2030 to a total of 768 thousand. However, this group will represent only 11 percent of the total population at that time.

High School Age

The 14-17 age group increased by 111 thousand people between 1950 and 2000 to a total of 330 thousand; a 51 percent increase. However, this age group's percent of the total population remained unchanged at six percent in both 1950 and 2000. It is projected this group's population will increase another 12 thousand persons, or four percent, to a total of 342 thousand in 2030. The group will then represent five percent of the total population.

College Age

Between 1950 and 2000, due largely to the baby-boom, the ranks of the 18-24 age group grew by 37 percent to 535 million people, while remaining at roughly ten percent of the total population. This group is expected to increase an additional 13 percent to a total of just over 600 thousand persons. However, this group's percentage of the total population is expected to drop to nine percent by 2030.

Younger Adults

The 25-44 age group has also seen a sizable increase in population between 1950 and 2000; 495 thousand people or 44 percent. This increase can again be attributed to baby-boomers moving into this age grouping during the later part of the 20th Century. Nearly one of every three Missourians, 1.6 million persons, was in this age group in 2000. The group is anticipated to see a modest increase of five percent between 2000 and 2030 to a final population of 1.7 million persons or 25 percent of the total population at that time.

Older Adults

The 45-64 age group increased 43 percent, or 374 thousand people between 1950 and 2000, for a final population of 1.3 million. By 2030, this group is estimated to grow by an additional 246 thousand, or 20 percent, to a final population of 1.5 million. The 45-64 age group represented 22 percent of the population in 1950, in 2000, and again in 2030.

The Elderly

The elderly have increased more consistently and proportionately than any age group. Persons age 65 and over represented ten percent of the population in 1950. By 2000, their ranks had risen to 13 percent of the total population and it is estimated that by 2030 this group will represent more than one-fifth of Missourians (21%). Between 1950 and 2000, the 65-and-over population grew by 85 percent to 755 thousand persons. This group is projected to grow by an additional 87 percent between 2000 and 2030 when their numbers are projected to swell to 1.4 million as the baby-boom generation progresses into this age category.

The 85-and-over age group has grown, and will continue to grow, even more rapidly. In 1950, this group represented roughly one-half of one percent of the total population and measured 21 thousand. By 2000, the group had increased to 99 thousand, an increase of 78 thousand persons and the group then represented two percent of the population. The group is expected to increase by another 78 thousand by 2030 when they will number 176 thousand or 2.5 percent of the population.

The increases in Missouri's elderly population, caused by increased longevity of the elderly and the baby-boom generation progressing into this age classification, likely will have the greatest impact on Missouri of any changes seen among the various age groupings.

Regional Population Trends

Population shifts among Missouri regions have followed similar patterns for many years. Shifts have been from rural agricultural areas to urban areas and to rural areas rich in recreational amenities. Projections show that these patterns will continue, and there will be more movement to urban fringe areas (Figures 2-5).

Figures 2 through 5: Missouri Population by County

Recent migration trends predict the outlook for the next thirty years to be large growth in the suburban counties around Kansas City, St. Louis, and Springfield with significant decline for St. Louis County and agricultural counties. Based on the projections methodology, all of the top ten fastest-growing counties will be metropolitan counties.

Both Christian County, south of Springfield, and Lincoln County, northwest of St. Louis, should more than double in size by 2030. St. Charles County, northwest of St. Louis, is expected to grow by 76 percent. Around the Kansas City area, Cass, Clay, and Platte counties combined may grow as much as 62 percent.

With the lone exception of St. Louis County, all ten counties of greatest population decline are rural. New Madrid County is projected to lose more than a third of its population by 2030 and both Iron and Gentry counties could lose 30 percent. St. Louis County is projected to experience the largest numeric loss at just under 60 thousand persons.

Migration is the primary agent of population change in these areas of rapid growth and decline, and natural change sometimes accelerates the population shift. St. Charles County, for example, will gain 145 thousand net in-migrants over the next thirty years plus an additional 70 thousand persons through natural growth. The situation in New Madrid County is just the opposite. New Madrid County is projected to lose just under seven thousand people through out-migration by 2030 and an additional five hundred persons through natural decline. Even in St. Louis County, net out-migration is projected to play the largest part in population change. In the next 30 years, St. Louis County is projected to gain nearly 90 thousand persons through natural change, but these gains are over shadowed by out-migration of almost 150 thousand.

The ten most populous Missouri counties in 2030 based on these projections are listed in Figure 6. Although St. Louis County is projected to experience slight losses over the next thirty years, it will hold its position as Missouri's most populous county. Jackson County will also hold its position as number two.

Figure 6: Missouri Population by County

St. Charles County, the fourth most populous in 2000, is projected to overtake St. Louis City for the number three ranking in 2030 when its population nears the 500 thousand mark. Clay and Jefferson counties are expected to switch in the rankings between the number six and seven spots. And, Cass County is expected to overtake Franklin County for the number ten spot in 2030.

The projections used in this report have been generated using methods, inputs, and constraints which were deemed to be the most reasonable for all of Missouri's counties, as a whole. The projection model is designed to generate a reasonable expectation of what should happen to the population in each of Missouri's counties over the next 30 years based upon a series of carefully considered assumptions. As such, they are a valuable tool for planners, designers, policymakers, grant writers, and others interested in Missouri's future population trends.