College and Research Libraries


JAMES F. ANDERSON 

·Break- Even Point for a 

Proof Slip Operation 

This article applies break-even analysis to determine what magnitude 
of titles added ·per year (for which a proof slip will be used in pro-
ducing card sets) is sufficient to utilize economically Library of Con-
gress proof slips and a Xerox 914 copying machine in the cataloging 
operation of a library. A break-even formula is derived~ and an ex-
ample of its use is given using data gathered at Arkansas State Uni-
versity. 

THIS ARTICLE aims to derive. a formula 
which will determine the economic 
break-even point for the use of Library 
of Congress proof slips and a Xerox 
914 copying machine in the cataloging 
operation of a library. An example of 
the use of this formula will be given 
using statistics gathered from the cata-
loging department of the Arkansas State 
University library. 

As the numerous uses of LC proof 
slips in libraries have been elucidated 
in an article authored by Samuel W a-
ters and Salvatore Costabile, this article 
will focus upon the uses of proof slips 
only as they pertain to the. production 
of catalog cards. 1 Derivation of the for-
mula will not reflect the fact that most 
libraries using a Xerox 914 to reproduce 
catalog cards defray their rental costs 
through much more extensive use of the. 

1 Samuel T. Waters and Salvatore L. Costa-
bile, "The Proof of the Pudding: Using Library 
of Congress Proof Slips," CRL 27:87- 91 
(March 1967). 

Mr. Anderson was head cataloger, Arkan-
sas State Univl(rsity library at the time this 
article was tv1'itten. He is now director, 
First Regional Libmry, Hernando, M issis-
sippi. 

machine than through mere reproduc-
tion of catalog cards from proof slips; 
on the contrary, it will be assumed that 
the reproduction of catalog cards from 
proof slips must defray the entire cost 
of the Xerox 914. This assumption will, 
of course, necessitate a very conserva-
tive break-even point figure, and any li-
brary using the formula to determine 
whether or not to use proof slips should 
bear this in mind. One other advantage 
of proof slips which this formula does 
not account for is the time savings ac-
crued. The economic advantage of hav-
ing immediate access to proof slips over 
delaying cataloging while cards are or-
dered from the Library of Congress is 
very difficult to assess quantitatively, and 
is therefore not included in this analy-
sis. 

There are three constants and two 
variables which comprise this equation. 
The constants are defined as the. cost of 
LC card sets, the cost of Xeroxing a 
complete set of cards, and the cost of 
a proof slip subscription. The variables 
are the cost of student filing per year 
and the number of titles ordered per 
year .. While the latter is clearly a vari-
able dependent upon the individual li-
brary, the student filing cost varies only 

I 119 



... , 

120 I College & Research Libraries • March 1972 

as the types of arrangement, types of 
titles needed, and depth of proof slip 
file vary. 

The break-even point is derived when 
the cost of using proof slips in the cata-
loging process equals the cost of order-
ing Library of Congress cards for each 
title. Represented symbolically, this is 
defined as 

ax= bx + c + d 

where: 
a = cost of LC cards/set, 
b = Xerox cost for one set of cards, 
c = cost of proof slip subscription/year, 
d = cost of student filing/year, and 
x = number of titles added per year. 
When ( bx) is subtracted from both 
sides of the equation, the formula be-
comes: 

ax - bx = c + d, or 
x (a - b) = c + d 

The variable ( x) can then be isolated 
by dividing both sides of the equation 
by (a-b): 

c + d 
X=----

a- b 

Therefore, when the number of titles 
which would have a proof slip avail-
able is greater than the quantity : ~ ~, 
it would be more economical to use 
proof slips rather than order LC card 
sets for each title received. 

In order to suggest how this formula 
might be applied in a library, and to 
furnish statistics which other libraries 
might use in computing their fixed and 
variable costs for a proof slip operation 
of this type, an actual example is pre-
sented in the following section. It is al-
so hoped that this example will help 
clarify the usefulness of cost figures. 

When Arkansas State University de-
cided in 1967 to begin a subscription to 
Library of Congress proof slips, it was 
agreed that the basic need, as far as cat-
aloging was . concerned, was for current 

imprints in the English language. Ac-
cordingly, the procedure for handling 
proof slips,. ~-~-ge~d maintain-
ing a three-year file of proof slips of 
titles in the English language. This 
meant that upon receiving the weekly 
box of proof slips from the Library of 
Congress, all slips for books with a 
copyright date older than three years, 
as well as those for foreign language 
books, were discarded. The remaining 
slips were alphabetized by main entry 
and filed in the appropriate section of 
the catalog for the particular year in 
which the book was copyrighted. At the 
beginning of each new year, the oldest 
section was discarded, thus maintaining 
the three-year file. We found that a 
three-year file of English language 
proof slips could easily be housed in 
two sixty-tray catalogs. 

Over a one-year period, the number 
of hours spent each day sorting, alpha-
betizing, and filing proof slips were to-
taled by the filers in the cataloging de-
partment. These statistics totaled ap-
proximately 485 hours. This figure, mul-
tiplied by the hourly wage rate for stu-
dent workers, $1.60, yielded the figure 
$776, and accounts for variable "d" in 
the equation. The other fixed cost is 
quantity "c" in the formula, which is 
the yearly cost of a subscription to the 
proof slips. This cost, which is subject 
to change every year, was $385 last year. 

The two variable costs (costs that 
vary according to the number of books 
cataloged) are the cost of LC card sets 
and the cost of Xeroxing a card set 
from a proof slip. The cost of an LC 
card set was $.35. The cost of Xeroxing 
a card set was obtained by adding the 
average rental cost per card of a Xerox 
914 ( $.01) to the average cost per card 
of card stock ($.005), yielding a total of 
$.015 per card. The operator time for 
the Xerox 914 is not figured into this to-
tal, because it is assumed that this time 
is offset by the time saved by typing the 
call number on the proof slip to be 

I 

' 



Xeroxed, thereby eliminating the neces-
sity of typing the call number on each 
card in the complete set. Multiplying 
this figure by five, which is the average 
number of cards per set, we produced 
quantity "b" in the equation, a figure 
of $.075. 

When these figures are substituted in-
to the original equation: 

385 + 776 
x or 

0.35- 0.075 
X = 4222 

The reader should bear in mind that 
this figure is not the total number of ti-
tles which must be added each year in 

Break-Even Point I 121 

order to realize the economies of a 
proof slip subscription, but rather the 
total number of titles for which a 
proof slip must be used to produce card 
sets. 

It is the opinion of the author that 
a break-even analysis such as the one de-
scribed in this article can be a very use-
ful tool to librarians. Aside from th·e 
many other uses of proof slips, a medi-
um-sized library can realize a definite 
savings in processing costs by utilizing 
a proof slip subscription and a Xerox 
914 copier instead of ordering card sets 
from the Library of Congress.