Ranges of Income, Notes
Numbers Institute, PO Box 1320, Shepherdstown WV 25443, LR@NumbersInstitute.com
The poster shows typical incomes in 200 occupations. The data come from
surveys in 1992-1994, and have been converted to 1995 prices. The data include
a representative sample of US workers, with a few exceptions (see last
paragraph of Methodology). The figures include people who work for themselves,
as well as people who work for others.
Thickness of Lines. The thickest lines show the most common
occupations: managers, sales supervisors (including people who run their own
shops), secretaries, and truck drivers. These have millions of workers and
thousands of interviews in the sample. For example there are four million sales
supervisors, and 3,300 of them in our sample. The thinnest line represents
29,000 Optometrists.
Length of Lines. The length of each line shows the range of incomes
where most workers fall. Most people earn in this range. We hope you will not be
in the bottom fifth of workers, who earn less than the bottom of the line. We
do hope you will be in the top fifth of workers, who earn more than the top of
the line, but you should not count on it. You will probably be in the 3/5 of
workers who are somewhere along the line. Since 1995, and in the future, dollar
levels rise with inflation and economic growth, but the relative positions of
jobs change slowly, if at all.
Occupations and Jobs. Each line shows an occupation, or a group of
similar occupations. Jobs vary in each occupation, for example junior and
senior managers, small and large farmers, local and long distance truck
drivers. Earnings vary for these different jobs in each occupation. Earnings
also vary in different parts of the country; and for other reasons, causing the
variation of incomes shown by the length of each line.
Turnover. There is a scale of percents up and down the poster, labeled
in the left margin as Turnover. The range goes from very stable jobs at the
bottom left, to average turnover in the upper left. The scale continues in the
bottom right, and ends with the most transient jobs in the upper right, where a
third of workers change employers each year.
Turnover suggests job openings. Even more important, turnover measures job
quality: jobs where people stay are usually desirable. Different people have
different needs in their jobs, and a general survey cannot measure all aspects
of job quality, but turnover, like pay, is a starting point for thinking about
attractive and unattractive jobs. Notice that jobs with higher turnover usually
do not compensate with high pay. On the contrary, jobs with low turnover often
have the highest pay, which is part of the reason people don't leave these jobs.
Turnover includes people changing employers in the same field, as well as
people changing occupations. It includes changes from self-employment to
working for someone else, and the reverse. It does not include self-employed
people changing from one client to another, like a musician or electrician, nor
people starting their first job or retiring.
Women and Men. The dot on each line shows the fraction of workers
who are women. For example if the dot is a quarter of the way from the left end
to the right, a quarter of the workers are women. It is striking that
traditionally male and female jobs are still overwhelmingly male or female:
Firefighters, brick masons, carpenters, electricians and roofers are almost all
men. Secretaries, child care workers, dental hygienists and receptionists are
almost all women.
Women's and Men's Pay. There are tick marks at the top and bottom
of most lines. These show the median earnings of women and men (median means
half the women (or men) earn less than this point, half earn more). These
figures are not adjusted for type of work, experience, or education.
Women earn less, because of discrimination and because of these other reasons.
Ticks are omitted if samples are too small. Ticks can be to the left of
the line if the median income for one sex is less than the 20th percentile of
both sexes, (see "Supervisors, manufacturing," at 5% turnover).
Minorities. The poster does not compare data on minorities
and whites, though the story would be similar to the story for women and men.
The problem was with sample sizes in many occupations. Even for women, the
sample sizes were often not large enough to show separate data, and the samples
were smaller for minorities.
Part Time. The slash on each line shows the fraction of workers who
work less than 35 hours per week at their main job. (If the fraction is less
than 5%, it is not shown, to avoid crowding the end of the line.) This part
time fraction is quite low in most jobs. Working hours fell steadily in the US
from 1900-1940, and have fallen very little since. Some large employers, like
the US government, do give proportionate fringe benefits to part time workers,
based on hours worked. Even these employers have few part time workers. Other
employers give no benefits to part time workers (of course many employers give
no fringe benefits to anyone). People have spent their increased prosperity
since 1940 on larger homes for smaller households, on health care, and on
retirement, rather than on shorter work weeks.
For Guidance Counseling. A main
purpose of the poster is to help people think about jobs different from the
ones they know about. The poster can open people's eyes to the wide variety of
jobs. They can then read appropriate references, and talk to employers and
workers to find more information on these jobs in their local area.
A group of students can divide up interesting jobs, and (individually or
in pairs) do library research and interview companies and workers about these
jobs. It is great if students interview workers just a few years out of school,
to learn what experiences they had finding work and fitting in.
For Economics. The poster can
start discussions on earnings, turnover, supply and demand for labor,
transferability of skills, part time and full time work, economic power of
employers and unions, restrictions on entry (ranging from lawyers to carpenters
and hairdressers). Theory says that competitive employers with perfect
information will pay workers according to how productive the workers are (or a
little more, to reduce the cost of turnover). However, sometimes there is
little competition between employers, and unions reduce competition between
workers. Also, both employers and workers have poor information about worker
productivity, either before or after a worker is hired (especially in services,
where most people work). Therefore social expectations, luck and bargaining
determine pay too.
For Mathematics. Students can
draw similar graphs with other data, perhaps every 2-3 weeks. They can get data
from the web, almanacs and elsewhere: birth and death of presidents; number of
males and females in different TV shows, in literary works, and in textbooks;
present and future population of countries; crime or death rates for different
crimes or diseases, now and in the past; etc. If they design a very large
graph, they might add to it every 2-3 weeks.
Value Judgments. Readers react
to this poster with their own value judgments. Jobs with great skill, training
or stress usually, but not always, pay more than average. Do they pay enough
more or too much? Some jobs earn much less than others, even important, skilled
and stressful jobs, like child care workers. Why? Women earn consistently less
than men even in jobs like teaching, where most workers are women, and even
though many managers, including personnel managers, are women. What would it
take to reach equality? Many jobs are virtually all male or all female. How can
workers of the opposite sex break in and avoid harassment? People who want part
time work so they can pursue other interests or raise families, have a limited
choice of good part time jobs. How can they convince managers to pay salary and
benefits proportionately for part time work?
People
are shown at their actual weekly or monthly incomes, converted to an annual
total and to January 1995 dollars, using the Consumer Price Index. If they
worked 15-39 hours per week, we converted income to full time (40 hrs/wk)
equivalent. If they worked less than 15 hours per week, they are not in the
income figures, but they are included in the total number of workers, percent
part time, and turnover. If they worked 40 or more hours per week they are
included in all figures, without adjustment.
We pooled the data from three surveys, 1992-94, to increase sample sizes
and reliability. Every figure shown is based on a sample of at least 25
workers. This minimum sample size is a rule of thumb, which is also used in
Census Bureau publications, to minimize errors. Only the thinnest lines are
based on so few cases. Thicker lines show that in most occupations there are
more workers, and hence more sample size. An occupation is printed if there are
at least 25 workers reporting income in the occupation. The median income for
women (or men) is shown only if there are 25 women (or men) in the occupation.
Therefore a small occupation, like personnel managers (bottom right), with
relatively few men, shows no median income for men. Our sample has 51 personnel
managers: 35 women, and 16 men. For a few jobs, we cannot show median for
either women or men. Our sample has only 28 insurance underwriters (upper
left): 22 women and 6 men. Even some fairly common jobs have too few women to
show a reliable median for women, like carpenters, with samples of 3 women and
925 men (between 17% and 18% turnover). The total sample size for all
occupations included on the poster is about 61,000 workers. Weights are not
equal, since we had a greater sampling rate for self-employed people than for
others.
Notice for farmers, the line starts at zero, since the lowest 20% of
farmers actually lost money. The figures on the poster only include earnings
from the job, not income from other sources, like dividends or capital gains
from investments, or pensions from earlier jobs. This is a survey, so some
people may not have reported income accurately. The worst underreporting may be
for people with a lot of cash income.
For people who change jobs during a year, the original surveys did not
collect the total earnings from each job separately. We needed these totals, to
compare the actual earnings in different occupations. We took two different
approaches to obtain the needed data. Among people who worked for others, we
use earnings of the main job in the most recent week (middle of March each
year, since the survey was done in the third week of March), and multiply by 52
to have a full year of pay. This does not allow for the fact that in some jobs
full year work is not available, but it does put weekly earnings on a
comparable basis. Among people who were self-employed in the previous week, the
survey does not collect income for that week, but it does collect total
earnings in the previous year, number of weeks worked that year, and number of
jobs held that year. Therefore we based the earnings of self-employed people on
the self-employed who had only one job in the previous year (so all earnings
refer to the one job). This assumes that self-employed people who changed jobs
had similar incomes, while working, to people in the same occupation with one
job, but the effect is small. For the number of workers, turnover and percent
women, we included all self-employed people, so these figures are not affected
at all.
The surveys cover most workers who live in the US, whether citizens or
not. The surveys exclude the military, workers under 15 years old, and people
who are homeless or live in institutions (though those rarely have jobs). Data
for people who could not be found or refused to answer were estimated by the
Census Bureau, based on people who did answer. Besides those exclusions from
the survey, the poster excludes occupations that have very few workers, like
garbage collectors (sample of 20), statisticians (5) and trappers (1). The
Numbers Institute used the raw data for each worker, collected or estimated by
the Census Bureau; then grouped people into related occupations as necessary;
and calculated all the incomes and percentages shown on the poster.
Readings.
Books on jobs are in libraries under Dewey Decimal 331, 338 and 371. US
government reports describe many jobs: (a) Occupational Outlook Handbook, (b)
Selected Characteristics of Occupations Defined in the Dictionary of Occupational
Titles, (c) Area Wage Surveys, (d) Monthly Labor Review, (e) Employment
& Earnings (monthly), (f) Standard Occupational Classification
Manual. A private book, American Salaries & Wages Survey by
Merlita Reddy of Gale Research, summarizes many local surveys.
Many associations publish surveys of pay (eg professors, by college, in Chronicle of Higher Education every April; florists in Floral Finance). Students can find associations on the web and search for recent studies on pay in the occupations which interest them.