32 Monthly Labor Review August 2000

Technical Note Technical Note

Among the important economic indicators released by the Government

each month is the employment estimate

from the Current Employment Statistics

(CES) program.1 It is important for users

of CES data to understand how strikes

affect CES estimates so that they can accurately interpret the economic meaning

of the change in the number of employees over the month. Conceptually, the

CES survey measures the number of persons on payrolls—that is, those actually getting paid for work or for leave

that occurred during the reference pay

period. Thus, persons on strike for the

entire period are not counted as employed, because they are not on the payroll.2 The growth in employment over

the month is affected by the net change

in the number of strikers—the number

of persons newly on strike minus the

number who returned to work after a

settlement. If the net is positive (more

new strikers than returning workers), employment growth over the month is reduced; conversely, if the net is negative,

employment growth is boosted.

While the reflection of strikers as a

reduction in employment may cloud any

underlying trend analysis, it is exactly

the measure needed for other uses of

CES data. For example, CES data are a major input for generating estimates of personal income, part of the Bureau of Economic Analysis’ National Income and

Product Accounts. Also, besides employment, the CES program produces estimates of average weekly hours and average hourly earnings. The product of

employment, weekly hours, and hourly

earnings yields aggregate earnings,

which form the basis of the wage and

salary component of the Commerce

The impact of strikes

on current employment

statistics

Karthik A. Rao

Karthik A. Rao is an economist in the Division of Monthly Industry Employment Statistics, Bureau of Labor Statistics.

Department’s preliminary estimates of

personal income. If persons on strike were

included in the CES estimates, the aggregate earnings data would be inflated; estimates of the strikers’ earnings would

have to be “backed out” of the data used

to compute personal income. Another

major indicator that utilizes CES data is labor productivity, which divides output by

the number of hours that went into producing the output. CES data on aggregate

hours (employment multiplied by average

weekly hours) are used in this computation. If strikers’ hours were in the data,

analysts would have to eliminate them

before computing labor productivity.

Thus, for a variety of reasons, it is

important that strikes be identified and

accurately reflected in the CES estimates.

It also is important that persons using

CES data to analyze economic trends be

able to discount the effect of strikes in

the data. This technical note provides

an overview of how strikes can affect

CES estimates and of where to find current and historical information on the associated effects.

Strikes and employment

The largest strikes that have affected CES

estimates in the past 25 years are listed

in table 1. Three major factors determine

how, where, and to what extent strikes

affect the CES estimates: the reference

pay period, the industry code, and the

striking company’s presence in or absence from the sample.

Reference pay period. The most critical factor in determining whether a strike

will be reflected in CES estimates is its

timing. The CES reference pay period is

the pay period that includes the 12th of

the month. However, the length of pay

periods varies among establishments.

Because persons paid for any part of

the reference period are counted as employed, workers must be on strike for

their entire reference pay period in order to be excluded from CES employment

counts. In all of the examples in exhibit

1, we assume that the strikers’ January

reference pay period is from Sunday the

11th to Saturday the 17th and their February reference pay period is from Sunday the 8th to Saturday the 14th. When

the strikes end, all workers are called

back the next day. All plants involved

in the strike are included in our sample.

In addition, strikes may be rolling,

which means that a given strike may

start and end at different dates at various establishments. For example, the

1983 strike of 640,000 workers against

American Telephone and Telegraph

(AT&T) officially started on August 7

and ended on August 28. On August

15, 20,000 workers from Western

Electric’s City Workers of Oklahoma

joined the strike, thus bringing the total

number of striking workers to 660,000.

However, these additional strikers had

worked for part of the reference pay period, so they were counted as being

employed.

Industry code. The Standard Industrial Classification (SIC) system is used

by the CES program to place all of the

establishments in its sample in a specific industry.3 SIC codes range from one

to four digits. A four-digit SIC is the most

specific classification, a one-digit SIC the

most general. For instance, the two-digit

SIC 37 stands for transportation equipment, which includes everything from

cars and automobiles to guided missiles

and space vehicles. To further delineate

this industry, it is classified under SIC

code 372, “aircraft and parts,” which refers to anything dealing with the aircraft

industry, from air tubes to fuselage assemblies. The most precise SIC code for

aircraft production is the four-digit 3721,

“aircraft manufacturing.” When a strike

occurs, it is reflected in data at the fourdigit level and all the higher level aggregates that include the affected four-digit

industry.

A company with numerous establishments or work sites can be classified into many four-digit SIC codes. For

example, the subsidiary of an integrated
Monthly Labor Review August 2000 33

automobile company that produces the

steel for the body of a car may be classified into “blast furnaces” (SIC 3312).

However, the subsidiary that turns the

steel into auto parts may be classified

into “automotive stamping plants” (SIC

3465). Finally, the part of the automobile

company that actually assembles the car

may be classified into “motor vehicles

and passenger car bodies” (SIC 3711). As

a result, strikes against a single company

can sometimes be distributed across

several industries, affecting employment

levels in each.

Presence in the sample. The CES program is an establishment-based sample

survey of approximately 390,000 establishments. Known strikes are always

fully reflected in the estimates. However,

analysts who prepare the estimates often will have to make adjustments based

on the extent of the representation of

the striking company in the sample.

Some companies are completely represented, while others are only partially

represented or not represented at all. An

example of complete representation is a

company with 10 plants on strike, all of

which are in the usable sample at the

time the estimate is made. Partial representation is signified by a company with

10 plants on strike, but only 5 in the usable sample. No representation is indicated by a company with 10 plants on

strike, none of which are present in the

sample.

CES industry analysts must assure

that a strike is reflected in the CES estimates, regardless of its presence in the

sample. Strikes are most easily accounted for if the striking establishments are completely represented in the

CES sample. When this is the case, the

weight of the striking establishment is

adjusted so that the establishment represents only itself in the CES estimates.

If a particular strike is only partially or

not at all represented in the sample, analysts will make adjustments to the final

estimate in order to reflect all persons in

the strike. In this case, the number of

workers on strike usually is determined

by contacting the public relations office

of the strike-affected company or by

using a published figure that is consistent across a variety of public sources.

Effect on hours and

earnings estimates

Besides having an effect on CES employment counts, strikes also affect estimates

of workers’ average weekly hours and

average hourly earnings. These are

hours for which production workers either are paid for work or are on paid leave

(including paid vacation, holidays, sick

leave, or other paid leave) for the referExamples of effects of strikes on employment figures

Example 1:

Jan. 15

Feb. 5 2,000 No No None, because the

workers were

employed in some

part of January’s

reference week;

therefore, they are

counted as employed.

Example 2:

Jan. 20

Feb. 20 3,000 No Yes None. Strike began

after the January

reference pay

period.

Example 3:

Jan. 18

Feb. 6 5,000 No No None. Strike began

after the January

reference pay period.

On strike entire—

Effect on—

Number of

workers

involved

January

reference

period

Strike

begins

Strike

ends January

employment

February

employment

March

February employment

reference

period

None, because the

strike did not continue

through the end of

February’s reference

week. Workers were

back on payrolls and

counted as employed.

Employment level

 and over-the-month

change decrease

by 3,000.

None. Strike ended

before the February

reference pay period.

Employment

level and overthe-month

change increase

by 3,000.

...

...

Exhibit 1.
34 Monthly Labor Review August 2000

Technical Note

ence pay period.

When strikers work part, but not all, of

the reference pay period, the CES survey

counts them as employed, but with reduced hours. The magnitude of the reduction on average weekly hours depends

on the proportion of workers in the

industry’s sample with reduced hours and

the number of hours they worked.

When workers are on strike for an entire pay period, their hours and earnings

can be affected in two ways: through

within-industry effects and by sum-acrossindustries effects.

Within-industry effects. For the specific industry involved in the strike, estimates are affected only if the hours or

earnings of the persons on strike or layoff differ significantly from the industry’s average hours or earnings. The

impact is phased in slowly over the

months the strike continues. Because

of confidentiality requirements, the Bureau of Labor Statistics cannot provide

the precise impact of a particular strike and

related shutdowns on average weekly

hours or average hourly earnings for a

particular industry. However, the change

in the industry estimate will include the

impact of the strike, as well as developments reported by other members of the

sample. One example of the within-industry effect is the AT&T strike of 1983.

In late July of that year, AT&T workers

went on strike all across the country.

They were on strike for the full pay period that includes August 12. Table 2

shows the estimates of employment,

average weekly hours, and average

hourly earnings within the category of

“telephone communications, except radio” (SIC 4813) during the affected

months.

The August over-the-month employment decline of nearly 635,0004 in the

category of “telephone communications, except radio” and an average

hourly earnings decline of $0.30 include

the impact of the large strike of 640,000

workers against AT&T, as well as normal monthly fluctuations in other reporting establishments. The impact of the

AT&T strike was reversed when the strikers returned to work before the next survey reference period.

Sum-across-industry effects. The absence of persons on strike or layoff from

payrolls may affect average weekly

hours or average hourly earnings at

higher levels of industry aggregation. If

workers in the specific industry involved

in the strike work shorter hours or earn

less than workers in other industries in

the aggregation, the hours and earnings

estimates for the aggregation will be

higher. Conversely, if workers in the specific industry involved in the strike work

longer hours or earn more than workers

in other industries in the aggregation,

the hours and earnings estimates for the

aggregation will be lower.

For example, a strike in aircraft manufacturing (SIC 3721), which has higher

Strikes affecting CES employment by more than 50,000, 1975–2000

Year Month SIC Industry

1975 ............................ May 15 General building contractors: residential buildings 75,000

1976 ............................. May 301 Tires and inner tubes 59,900

1977 ............................. December 12 Coal mining 160,000

1978 ............................. January 12 Coal mining 160,000

1980 ............................. July 15 General building contractors: residential buildings 105,000

February 291 Petroleum refining 58,300

March 291 Petroleum refining 59,200

1981 ............................. April 12 Coal mining 160,000

May 12 Coal mining 162,000

June 15 General building contractors: residential buildings 51,300

1983 ............................. August 481 Telephone communications (AT&T) 640,000

1986 ............................. June 481 Telephone communications (AT&T) 86,100

1987 ............................. September 82 Educational services 52,000

1989 ............................. August 481, 5063,

7374 Telephone communications; electrical apparatus and

equipment, wiring supplies, and construction materials;

computer processing and data preparation and processing

services 125,000

September 481 Telephone communications (NYNEX) 53,500

October 481 Telephone communications 53,500

November 481 Telephone communications 53,500

1994 ............................. April 42 Motor freight transportation and warehousing 70,000

1997 ............................. August 421 Trucking and courier services, except air

(United Parcel Service) 185,000

Impact on CES

 employment1

Table 1.

1

 The amount by which CES employment levels are lowered due to

workers on strike. The figure does not include related layoffs or other

secondary effects of the strike.

NOTE: Table does not include strikes that occurred outside the CES reference period.
Monthly Labor Review August 2000 35

weekly hours and hourly earnings than

the other two four-digit industries within

the category of “aircraft and parts” (SIC

372), would lower average hours and

hourly earnings estimates for the aircraft

industry (SIC 372). Estimates for transportation equipment (SIC 37) and the entire manufacturing sector would be similarly affected if hours and earnings in

aircraft were higher than in these aggregate-level industries. The magnitude of

this effect is directly related to the number of persons on strike.

Secondary effects

of a strike

Among the potential secondary effects

of a strike is that on establishments

which are not on strike, but are dependent on the striking establishment. A

good example of this is the General Motors (GM) strike of 1998.

On June 5, 1998, 3,000 employees

went on strike at a GM fabricated-metalstamping plant in Flint, Michigan. One

week later, an additional 5,800 workers

went on strike at a parts plant in Flint.

Both strikes ended on July 29. The strike

occurred at only those two plants. However, because the plants were critical to

GM’s supply chain, the strike had a disproportionate effect on production. Automobile assembly plants that relied on

parts from the striking establishments

were forced to shut down. All told,

150,000 employees were out of work, due

to the primary and secondary effects of

the strike. (See table 3.) Furthermore,

many of these workers were not in the

same industry as the original plants on

strike. The affected industries included

gray and ductile iron foundries (SIC

3321), motor vehicles and passenger car

bodies (SIC 3711), and even the help

supply industry (SIC 7363).

To assess the effect of the strike on

CES hours and earnings estimates, the

July estimates were recalculated using

the manufacturing industry employment weights for June instead of July.

The reason for the recalculation was to

ignore any possible effects of the lower

number of workers in the relatively highpaying auto-related industries because

of the strikes and shutdowns. Table 4

shows the effect on the change in average hourly earnings over the June–July

and July–August periods.

Average weekly hours were unaffected by the recalculation. While the

exercise shows the effect of all shifts in

the distribution of employment across

manufacturing industries between June

and July, the most important shift was

the reduced weight of the high-paid

auto industry. Thus, the results can be

attributed primarily to the auto strike.

Average hourly earnings would have

been about 5 cents higher in manufacturing, but less than 1 cent higher at the

total private-industry level if the workers affected by the strike had remained

on payrolls in July.

Another secondary strike effect occurs when competitors of a striking firm

add employees to cover additional business foregone by the striking company.

This effect may even offset the magnitude of the strike’s primary effect on CES

data. A case in point is the strike by

185,000 United Parcel Service (UPS)

workers on August 5–20 of 1997 (including the entire reference pay period). The

temporary removal of UPS from the delivery services market led to increased

business for its competitors. Table 5

shows the impact on air courier services

(SIC 4513) owing to the strike against

UPS.

Despite the fact that 185,000 UPS

workers were on strike, the total loss of

employment in the industry was only

166,000. The 19,000-employee difference

was determined, in part, to be the result

of other air courier services hiring workers to take advantage of their increased

business.

CES estimates of employment and of average hours and earnings of

telephone communications (except radio) workers (SIC 4813)

during 1983 AT&T strike

Average Average

weekly hourly

hours earnings

Levels:

July 1983 .......................... 985.0 40.4 $11.36

August 1983 ...................... 350.1 40.3 11.06

September 1983 ................ 976.3 40.5 11.51

Over-the-month changes:

July–August ...................... –634.9 –.1 –.30

August–September ............ +626.2 +.2 +.45

Month and year

All

employment

(not

seasonally

adjusted)

Table 2.

Effect of 1998 strike against General Motors on CES employment

Category June July

 Total ................................. –9,400 –140,600 –150,000 +150,000

On strike ............................ –3,400 –5,800 –9,200 +9,200

On layoff ............................ –6,000 –127,800 –133,800 +133,800

Total, on strike and

on layoff .......................... –9,400 –133,600 –143,000 +143,000

Help supply industry

(secondary effect) ........... (1

) –7,000 –7,000 +7,000

1

 No one on strike or on layoff in help supply industry.

in manufacturing

Total

declines

August

returns

Table 3.
36 Monthly Labor Review August 2000

Technical Note

Replacement workers

Sometimes the management of establishments on strike hires workers to do the

jobs of the workers on strike. The new

workers are known as replacement workers. The hiring of replacement workers can

complicate the estimation of a strike’s impact. If replacement workers are hired immediately, then the strike will not be reflected at all in CES data. Furthermore, if

replacement workers are hired later during the course of an ongoing strike, their

presence may falsely indicate that the

strike is over even if it is not. To further

complicate matters, replacement workers

could permanently displace the strikers,

or they could instead be just a temporary

solution and be laid off when the strike

ends. In dealing with the issue of replacement workers, it usually is not possible to

draw conclusions directly from CES data.

Instead, one must rely on public reports,

company news, and other sources for

such information. The Bureau’s pledge of

confidentiality to its respondents precludes revealing any company-specific

information not generally available to the

public.

CES strike report

BLS staff prepare a monthly summary of

strike activity during the survey reference pay period. This CES strike report

contains information about workers directly involved in large strikes (stoppages of 1,000 or more workers) who

were idle during the entire reference pay

period.5 The information comes from

public sources, and the report itself is

prepared and released before any survey data are compiled. The numbers in

the report indicate the possible direct

effect of strikes on CES employment estimates for the current month. Thus, the

strike report may be useful to persons

who are trying to anticipate the upcoming payroll survey data. Also, after the

monthly CES estimates are released, analysts attempting to discern underlying

economic trends can use the strike report to exclude movements caused by

strikes.

The strike report includes information

on the number of workers on strike during

the current and previous reference periods, new strikes, strikes settled, and the

net change. Information is provided on

specific strikes and the industries they affect. There are two ways to use the report:

1. Add the total number of people on

strike the current month to the

overall level of employment to see

the level with the strike effect

 removed.

2. Add the net change in the number

of persons on strike to the current

over-the-month employment

change to remove the effects of

strikes.

While the numbers in the strike report

are useful to analysts, it is important to

note that the figures should be used with

caution, as they are preliminary and possibly incomplete. The Bureau of Labor

Statistics makes every reasonable effort

to ensure the accuracy and completeness of the strike report; however, because the report is based on secondary

sources, the Bureau cannot guarantee

its accuracy or completeness.

Strike-adjusted

employment data

Information on strikes that affect CES

employment data is available starting

with 1975 and is used as input for the

seasonal adjustment process. For the

study presented in this technical note,

the information was used to compute the

net effect of those strikes each month.

The net strike effect was then added to

the official over-the-month change in

employment to compute a strike-adjusted series—that is, a series which removes the effect of strikes. This series,

presented in table 6, is a better indicator

of underlying economic trends than the

official series is. The strike-adjusted historical series also is useful if an analyst

Effect of 1998 strike against General Motors on CES estimates

As published Difference

Manufacturing:

June–July ..................................... $–0.03 $+0.02 $0.05

July–August ................................. +.11 +.06 –.04

Total private:

June–July ..................................... +.03 +.04 +.01

July–August ................................. +.07 +.06 –.01

of over-the-month changes in average hourly earnings

Recalculated

without

strike effect

Over-the-month change

Sector and months

Table 4.

CES estimates of employment, average weekly hours, and

average hourly earnings of air courier services workers

(SIC 4513) during 1997 UPS strike

Levels:

 July 1997 ........................................ 464,000 28.8 $14.78

 August 1997 ................................... 298,000 33 15.48

 September 1997 ............................. 468,000 37.5 14.50

Over-the-month changes:

 July–August .................................... –166,000 4.2 .70

 August–September ......................... 170,000 4.5 –.98

Table 5.

Levels and

 over-the-month

changes

All employment

(seasonally

adjusted)

Average

hourly earnings

Average

weekly hours

Recalculated

without
Monthly Labor Review August 2000 37

Over-the-month change in employment, excluding the effect of strikes, seasonally adjusted, all employees

[In thousands]

Year January February March April May June July August September October November December

 1975:

Official series ...... –420 –403 –323 –121 161 –71 238 354 208 311 120 296

Net strike

activity ............. – –5 3 33 20 –12 84 –79 15 –44 –9 14

Series excluding

strikes .............. – –408 –320 –88 181 –83 322 275 223 267 111 310

1976:

Official series ...... 411 280 213 315 58 66 227 96 261 0 299 197

Net strike

activity ............. –44 –4 11 32 93 –26 54 –55 –74 15 –25 –30

Series excluding

strikes .............. 367 276 224 347 151 40 281 41 187 15 274 167

1977:

Official series ...... 179 277 427 389 367 404 379 214 457 230 370 240

Net strike

activity ............. 2 15 16 –26 39 –7 24 24 –34 60 –9 90

Series excluding

strikes .............. 181 292 443 363 406 397 403 238 423 290 361 330

1978:

Official series ...... 193 344 530 745 321 407 226 287 110 363 452 310

Net strike

activity ............. –12 0 –18 –144 5 3 25 11 5 –26 –19 –5

Series excluding

strikes .............. 181 344 512 601 326 410 251 298 115 337 433 305

1979:

Official series ...... 169 257 441 –63 318 274 64 140 –10 211 106 151

Net strike

activity ............. 2 10 –4 55 –14 –14 –13 2 19 23 29 –48

Series excluding

strikes .............. 171 267 437 –8 304 260 51 142 9 234 135 103

1980:

Official series ...... 112 147 119 –215 -464 –342 –298 288 82 288 216 224

Net strike

activitiy ............ –55 59 –3 –13 –19 –6 133 -49 –16 –47 –24 –8

Series excluding

strikes .............. 57 206 116 –228 –483 –348 –165 239 66 241 192 216

1981:

Official series ...... 229 92 111 13 –77 143 125 –90 –129 25 –202 –183

Net strike

activity ............. –11 –3 8 177 21 –129 –32 –23 15 –15 –21 1

Series excluding

strikes .............. 218 89 119 190 –56 14 93 –113 –114 10 –223 –183

1982:

Official series ...... –383 26 –137 –306 –66 –262 –323 –203 –182 –208 –138 26

Net strike

activity ............. 4 0 6 6 5 24 –34 21 3 –3 –5 –6

Series excluding

strikes .............. –379 26 –131 –300 -61 –238 –357 –182 –179 –211 –143 20

1983:

Official series ...... 151 –68 188 265 286 389 427 –340 1,115 320 319 383

Net strike

activity ............. 2 5 0 –1 –11 0 30 674 –678 9 –23 –5

Series excluding

strikes .............. 153 –63 188 264 275 389 457 334 437 329 296 378

1984: .......................

Official series ...... 414 519 269 338 302 373 322 238 301 313 330 168

Net strike

activity ............. –16 –6 6 17 –8 13 –11 63 –77 9 5 26

Series excluding

strikes .............. 398 513 275 355 294 386 311 301 224 322 335 194

1985:

Official series ...... 252 148 337 162 267 117 185 231 182 220 188 214

Net strike

activity ............. –41 –1 28 –24 –6 12 –8 32 –5 –5 3 1

Series excluding

strikes .............. 211 147 365 138 261 129 177 263 177 215 191 215

1986:

Official series ...... 99 119 78 178 122 –123 303 159 312 233 165 249

Net strike

activity ............. –32 0 11 –2 –1 167 –145 42 –31 4 –2 0

Series excluding

strikes .............. 67 119 89 176 121 44 158 201 281 237 163 249

1987:

Official series ...... 149 229 233 362 197 149 334 219 164 550 220 344

Net strike

activity ............. 0 –31 –6 –9 6 0 7 –1 55 -60 0 –5

Series excluding

strikes .............. 149 198 227 353 203 149 341 218 219 490 220 339

on total nonagricultural payrolls, 1975–2000

Table 6.
38 Monthly Labor Review August 2000

Technical Note

Continued—Over-the-month change in employment, excluding the effect of strikes, seasonally adjusted,

[In thousands]

Year January February March April May June July August September October November December

all employees on total nonagricultural payrolls, 1975–2000

1988:

Official series ...... 79 423 265 226 274 321 268 199 215 277 277 323

Net strike

activity ............. 0 4 11 –8 1 5 16 –4 –7 –6 –11 0

Series excluding

strikes .............. 79 427 276 218 275 326 284 195 208 271 266 323

1989:

Official series ...... 302 251 194 199 101 100 95 115 130 112 281 121

Net strike

activity ............. 2 3 27 4 0 11 10 97 –68 4 –6 –72

Series excluding

strikes .............. 304 254 221 203 101 111 105 212 62 116 275 49

1990:

Official series ...... 254 317 198 38 291 79 –162 –164 –86 –183 –200 –109

Net strike

activity ............. 0 –3 16 –5 –3 –1 0 2 –2 –1 4 1

Series excluding

strikes .............. 254 314 214 33 288 78 –162 –162 –88 –184 –196 –108

1991:

Official series ...... –206 –259 –170 –185 –38 93 –69 84 8 –14 –94 6

Net strike

activity ............. –3 –6 –2 –2 5 –6 4 –2 2 –1 8 1

Series excluding

strikes .............. –209 –265 –172 –187 –33 87 –65 82 10 –15 –86 7

1992:

Official series ...... –37 –7 42 182 194 46 54 146 66 134 178 147

Net strike

activity ............. –3 0 –-3 1 –2 –3 –9 0 12 –8 –4 0

Series excluding

strikes .............. –40 –7 39 183 192 43 45 146 78 126 174 147

1993:

Official series ...... 236 314 –67 306 343 141 205 213 247 321 255 254

Net strike

activity ............. 0 5 –5 4 9 –4 3 5 0 2 –4 –18

Series excluding

strikes .............. 236 319 –72 310 352 137 208 218 247 323 251 236

1994:

Official series ...... 268 230 450 368 347 283 353 340 307 255 406 277

Net strike

activity ............. 0 0 0 74 –70 5 9 5 10 –1 –2 –15

Series excluding

strikes .............. 268 230 450 442 277 288 362 345 317 254 404 262

1995:

Official series ...... 317 288 156 185 –34 194 114 306 220 125 157 172

Net strike

activitiy ............ –1 0 0 –1 0 –2 0 3 7 23 1 –41

Series excluding

strikes .............. 316 288 156 184 –34 192 114 309 227 148 158 131

1996:

Official series ...... –69 489 236 175 344 264 196 278 151 248 266 217

Net strike

activity ............. 30 –27 1 –3 0 21 –9 0 –5 –3 0 0

Series excluding

strikes .............. –39 462 237 172 344 285 187 278 146 245 266 217

1997:

Official series ...... 203 295 347 294 259 226 296 71 431 318 292 324

Net strike

activity ............. 0 0 –3 4 7 –5 0 175 –183 –1 0 0

Series excluding

strikes .............. 203 295 344 298 266 221 296 246 248 317 292 324

1998:

Official series ...... 290 193 182 244 353 217 99 378 244 208 262 347

Net strike

activity ............. –1 3 0 0 0 10 0 –12 6 –2 2 –1

Series excluding

strikes .............. 289 196 182 244 353 227 99 366 250 206 264 346

1999:

Official series ...... 177 420 171 228 95 253 268 159 208 258 265 250

Net strike

activity ............. –1 –1 0 7 0 0 0 –7 0 –1 0 0

Series excluding

strikes .............. 176 419 171 235 95 253 268 152 208 257 265 250

2000:

Official series ...... 349 95 527 414 231 – – – – – – –

Net strike

activity ............. 0 15 –15 5 –3 – – – – – – –

Series excluding

strikes .............. 349 110 512 419 228 – – – – – – –

 NOTE: Dash indicates data not available.

Table 6.
Monthly Labor Review August 2000 39

wishes to compare estimates of current

employment growth with monthly

changes in earlier years, because strikes

can significantly mask other economic

activity and introduce volatility into the

data.

AN UNDERSTANDING OF THE TREATMENT OF STRIKES in the CES employment data is necessary for a correct

analysis of monthly movements. Depending on its timing compared with the

survey reference period, a strike can

have various impacts on employment,

average weekly hours, and average

hourly earnings. Further, if the company

affected by the work stoppage has

weekly hours or hourly earnings that

differ significantly from the industry average, the strike can have a large impact

on average weekly hours or hourly earnings for the industry. Similarly, if the industry involved in the strike has hours

and earnings that differ significantly

from higher level aggregates, the strike

can have an impact on the higher level

estimates of average hours or hourly

earnings.

Large strikes are widely reported in

newspapers around the country. Information from such public sources is used

to compile a summary of strike activity

each month. This report is made available on the Internet. The purpose of the

summary is to provide an early indication of the direct impact that strikes involving at least 1,000 workers will have

on the employment estimates, which are

released the following week.

In addition to their direct impact,

large strikes sometimes have secondary

effects, as, for example, when they

oblige other plants to close because

parts are in short supply. When the

magnitude of significant secondary

strike effects is known, like the direct

effects, these secondary effects are discussed in the monthly news release The

Employment Situation, the periodical

Employment and Earnings, and other

BLS publications.

Notes

1

 The Bureau of Labor Statistics cooperates with State employment security agencies

in the CES survey to collect data each month

on employment, hours, and earnings from a

sample of about 380,000 nonfarm establishments (including government). From these data,

a large number of employment, hours, and earnings series in considerable industry and geographic detail are prepared and published every

month. The employment data include series on

all employees, women workers, and production

or nonsupervisory workers. Hours and earnings

data include average weekly hours, average

weekly overtime hours, and average hourly and

weekly earnings. The CES is the source of the

“payroll,” or “establishment,” data that appear

in the Employment Situation news release, usually on the first Friday of each month, with

data for the previous month.

2

 This approach differs from that of the

Current Population Survey, which counts as

employed all civilian workers who have a job

during the survey reference period, including

those “with a job, but not at work”—the category that strikers are in.

3

 The CES program will convert from the SIC

system to the North American Industrial Classification System (NAICS) in June 2003.

4

 The fact that the decline was less than

640,000 indicates that without the strike, the

four-digit SIC industry would have gained 5,000

jobs.

5

 The strike report, which is generally released the Friday before the Employment Situation is released, is available on http://

stats.bls.gov/ceshome.htm, or it may be accessed by calling (202) 691-6555, the general

CES information number.