EVALUATING INTEGRATION AMONG LESS DEVELOPED COUNTRIES

LAFTA as a Case Study

BY CHARLES PEARSON

INTRODUCTION

THE difficulties of applying the tools of traditional customs union theory to evaluation of integration among less developed countries are well known.1 Techniques for estimating trade creation and trade diversion are generally considered inadequate, for at best they measure the static allocative efficiency of integration and skirt the important problem of assessing its development contribution.

The purpose of this paper is to develop a fiamework appropriate for the investigation of economic integration among less developed countries, and to ap ly this framework to the experience of the Latin

here does not pretend to be definitive, but rather it attempts to utilize available data for additional insight into the process and progress of integration.

If the fiamework is to be of practical interest it should, in addition to focusing on the development contribution, also accept the political nature of the integration process. As a minimum it should recognize that the relevant decision-making units in integration are nations and, consequently, reciprocity among the members is of central analytical importance.2 The task is to construct a system for measuring the development contribution of integration which is in accord with its political character.

American Free Tra B e Association (LAFTA). The approach employed

FRAMEWORK EMPLOYED

Three related dimensions of development are selected for investigation. They correspond to the widely endorsed integration objectives of growth contribution, industrialization, and export diversification. The concept of ‘integration-induced export stimulation’, disaggregated by

* I would like to acknowledge the helpful comments of Messn. Tom Davis, Isaiah Frank, Rolf Ludders, Chandler Morse and Jaroslav Vanek, all of whom have read earlier versions of the material presented here.

2 As used here reciprocity should be broadly interpreted to convey the meaning of more or less equal sharing of integration benefits by all members.

262

I N T E G R A T I O N A M O N G LESS DEVELOPED C O U N T R I E S 263

member country and by export product group, is introduced to serve as a measure of these dimensions. It is defined as the value of exports which a member country secures over and above the value it would have obtained had it not been a member, yet the integration scheme existed. Total stimulation by country will be related to growth contribu- tion, while disaggregation by export product group will allow measure- ment along the diversification and industrialization dimensions. Taken together the three dimensions will permit quantitative discussion of reciprocity.

The definition of export stimulation reflects the vantage point of an individual country which views the integration scheme as a parameter, and forms its participation decisions accordingly. The viewpoint is adopted to satisfy the condition that decision makers in integration are in fact national units. If membership is relatively large and economic power within the area reasonably dispersed analysis incorporating this vantage point seems desirable.

Thus formulated, the problem is to subtract from the observed value of exports, the hypothetical value which would have been forthcoming without membership.3 The observed values are available fiom the statistical publications of the member countries. Hypothetical values are estimated using a benchmark technique in which exports to the rest of the world serve as control groups.

Using the symbols

Lei, Lli, & i s Rli, Vt where :

L is the value of exports to the integration area (LAFTA) ; R is the value of exports to the rest of the world; V is the value of integration induced export stimulation ; o and I, the first subscripts, refer to the base year immediately

preceding the start of integration and some later year; i, the second subscript, refers to the ith export product;

then the percentage increases in exports to the two markets, denoted Li’ and Ri’, are:

3 Although trade creation/diversion analysis is deemed inappropriate in the context of this paper it nevertheless supports the hypothesis that integration will stimulate member country exports. See for example the analysis presented by D. Humphrey and C. Ferguson, ‘The Domestic and World Benefits of Customs Unions’, in Economia birernarionale, Vol. XIII, 1960, p. 197. The important point here is that both trade diversion and trade creation lead to increased demand for partner country output, and it is immaterial to the partner country whether rising demand for its output results from trade creation or trade diversion.

264 J O U R N A L OF C O M M O N MARKET STUDIES

Assuming for the moment that variables affecting exports to the two markets move proportionally within the control group (exports to the rest of the world) and the group under examination (exports to LAFTA), the differential rate of increase to the two markets will reflect the preferential market secured by membership in the integration area. The value of integration-induced export stimulation for the ith export commodity is then given by,

V, = (Li’ -Ri’)Lo,.4

The comparison technique is useful because it is not necessary to assume that all variables entering the export functions remain constant, but rather that a variable common to the L and the R functions will change proportionally in both. The measure is refined by recognizing that demand conditions in the two markets may not change by the same proportion. The more reasonable assumption is made that the country would share in demand changes arising in LAFTA and directed toward non-members. Using W,’ and N,‘ as the percentage change in the rest of the world imports and the percentage change in LAFTA imports from non-members respectively, the adjusted measure becomes,

V, = [(Lf’ - Ni’) - (Ri‘ - Wi)]Lof = (L,* - R,*)LOi

whereL,* = Lt‘-Ni‘, R,* = Ri’- W,’. DATA

This framework was applied to the experience of eight LAFTA inembers and the results are reported herein. The primary trade data sources were the Foreign Trade Yearbooks published by the Statistical Offices of the LAFTA countries, LAFTA’s Statistical Series No. 2, and commodity trade statistics published by the OECD.5 When possible the base year values were taken to be the average of 1960 and 1961 exports, and the subsequent observation was the average of 1966 and 1967 values. When required, conversion of domestic currencies to U.S. dollars followed exchange rate information published by the International Monetary Fund in its International Financial Statistics. The Foreign Trade Yearbooks give export values in considerable detail by product and by country of destination. Unfortunately, a uniform

4 V = observed value minus hmothetical value

i th; Appendix.

I N T E G R A T I O N A M O N G LESS D E V E L O P E D C O U N T R I E S 265

classification system has not been used by all members in reporting. The adoption of a common nomenclature for the region, NABALALC, based on the Brussels Tariff Nomenclature, is a welcome step. In an effort to permit systematic inter-country comparisons by product groups in this study the Standard International Trade Classification system (SITC) was selected, and export values for one-digit and two- digit levels of disaggregation were compiled. Exports reported in national classification systems were converted into the SITC with the aid of U.N. and LAFTA publications, and through concordances con- structed especially for this study.6

Table I presents the value of integration-induced export stimulation, by member country, disaggregated to the one-digit SITC level, and Table I1 shows stimulation at the two-digit level. Table 111 gives the total value of export stimulation for the LAFTA members.7

INTERPRETATION

The premise of the paper is that export diversification, industrialization, and growth contribution are three important objectives of integration among less developed countries, and that progress toward them can be measured by the export stimulation data as presented in Tables 1-111.8 These objectives are examined in turn.

The measure of export stimulation employed here is the value of export stimulation of non-traditional exports where traditional exports are considered to be those which comprise the four largest SITC Divisions (two-digit level). Consider Table IV. Column z is the percentage of total exports accounted for by the four largest export products, and therefore provides a rough indication of initial relative export concentration of LAFTA countries. Column 3 is the total value of export stimulation (summing at the two-digit level) and column 4 is the value of stimulation of non-traditional exports-that is, the value of stimulation of those products not considered to be traditional

6 United Nations, Department of Economic and Social Affairs, Standard lniemarional Trade Classification, Revised (Series M, No. 34), New York, 1961.

Asociacion Latinoamericana de Libre Comercio, N~menclarura Arancelaria para la Rcociacion Latitioamericana de Libre Comercio, Montevideo, 1965.

7 Note that a blank in Table I or I1 implies that the country did not export the product in question, that the value of export stimulation could not be computed, or that the expected pattern of L,* > R,* did not obtain. Consequently the value of export stimulation at the two- digit level does not sum to the value of stimulation at the one-digit level. Table I11 is constructed by summing at the two-digit level.

8 Two theoretical articles have appeared in which integration is analysed under the explicit assumption that industrialization has independent value. See C. A. Cooper end B. F. Massel, ‘Toward a General Theory of Customs Unions for Developing Countries’, Journal qf Political Economy, Vol. LXXIII (Oct. 1965). and H. Johnson, ‘An Economic Theory of Protectionism, Tariff Bargaining and the Formation of Customs Unions’,]ournal of Political Economy, Vol. LXIII (June 19651, P. 256.

r_r 0

C

TABL

E I - P 2 r r

EX

POR

T S

TIM

UL

AT

ION

BY

LA

FTA

MEM

BER

AN

D P

RO

DU

CT

GR

OW

*

Arge

ntin

a Br

azil

Chile

Co

lom

bia

Eiu

ador

M

exic

o Pa

ragu

ay

Peru

$ c)

0

o

Food

and

Liv

e A

nim

als

36.7

32

20,5

40

51s

8,69

5 3,

992

8,844

5,10

1 E

I Be

vera

ges a

nd T

obac

co

196

97

3 62

234

3

2

Cru

de M

ater

ials,

Ined

ible

16

,299

4.

087

1,1

35

24

s 10

,996

7,

854

11,1

03

0

3 M

iner

al F

uels

1,68

8 I

781

1,31

6 2,

187

‘2 z *

4 Fa

tsan

dOds

14

.310

39

8 58

30

5

Che

mic

als

9,51

4 1,608

4,08

1 56

8 20

3 7,

060

74

4-

1,

262

3:

914

9,48

3 7,

822

6,11

4 33

0 8,

996

M

7 M

achi

nery

and

Tra

nspo

rt

2,11

7 85

7 80

4,

987

+I

8 M

isce

heou

s M

anuf

actu

res

3.38

4 39

73

94

vl 2 Ei

SIT

C S

ectio

n

(thou

sand

s U.S

. dol

lars

)

6 M

anuf

actu

res,

by M

ater

ial

*See

App

endi

x fo

r data sources.

M

vl

0

TABL

E Ii

EXPO

RT

STIM

ULA

TIO

N B

Y L

AFT

A M

EMB

ER A

ND

EX

POR

T PR

OD

UC

T

2 SZTC D

ivisi

on

Arge

ntin

a Br

azil

Chile

Co

lom

bia

Ecua

dor

Mex

ico

Para

guay

P

m

2 !a * 2 13

.7

598.

1 2'

9 0

00

Live

Ani

mal

s 9,

388-

6 33

8.8

71-2

0

1

Mea

ts 10

,079

'9

128.

2 13

'9

42

1224

z

02

Dai

ry P

rodu

cts

04

0

1

03

Fish

65

-2

528.

7 40

4'4

8.9

72

04

Cer

eals

27.8

498

1,11

5'1

1,24

03

732.

6 6,

0207

5

2'5

05

Fr

uits

and V

eget

able

s 5,

990'

4 6.

3508

2,

191'

4 1,

245.

6 37

09

0

07

Cof

fee,

Tea

, Coc

oa S

pice

s 2,

2810

2 1,

148.

6 4,

1245

1,

5306

44

4'7

311.

2 84

'4

08

Ani

mal

Foo

dstu

ffs

4344

12

.6

13.1

98

8.4

og

Misc

ella

neou

s Foo

d Pr

epar

atio

ns

1'4

3396

82

.0

iz 11

Bev

erag

es

02

c 12

To

bacc

o 25

2'4

96.7

25

96

t- 2

1

Hid

es a

nd S

kins

4,

468.

0 22

.5

22.5

2

22

Oil

Seed

s, O

il Nuts

84.8

B

23

Cru

deR

ubbe

r 3.

327'

1 44

.3

00

1

0

9'5

0

24

Woo

d, L

umbe

r 30

'7

25

Pulp

and

Was

te P

aper

2,

2529

C 2

28

Met

allif

erou

s O

res

I04

I9

44

2.8

B

32

Coa

l 5'

3 (thousands U

.S. d

olla

rs)

588.

1 0 z

06

Suga

r 19

3'3

758.

9 12

.1

1,48

89 r

v1 m r,

26

Text

ile F

iber

s 16

,005

9 2,

6449

1,

186.

6 6,

455'

1 1,

498.

0 16

,685

4 Z 4

27

Cru

de M

iner

als

and

Ferti

lizer

s 1,

02S

'I 25

05

2397

1'

7

29

Cru

de M

ater

ial,

n.e.s

. 27

1.8

132.

7 53

.1

2.8

1,27

6.2

110.

8 v, w -

Arge

ntin

a Br

azil

Chi

le

Colo

mbi

a M

exico

Pa

ragu

q Peru

SITC

Div

ision

~ 33

Pe

trol

eum

34

Gas

35

E

lect

ricE

nerg

y 41

Ani

mal

Oils

andF

ats

42 Fixed

Veg

etab

le O

ils

43

Proc

essF

atsa

ndO

ils

51

Che

mid

Ele

men

ts

52

Coa

l and

Pet

roch

emic

als

53 Dyeing a

nd T

anni

ng M

ater

ids

54

Phar

mac

eutic

als

55

Esse

ntia

l Oils

, Soa

ps

56

Man

ufac

ture

d Fe

rtili

zer

57

Exp

losiv

es

58

Plas

tics,R

esin

s 59

Oth

er C

km

ids,

n.e

.s.

61

Leat

her

and

its

Man

ufac

ture

s 62

Rub

ber a

nd it

s M

anuf

actu

res

63

Woo

d an

d its M

anuf

actu

res

64

Pape

r an

d its M

anuf

actu

res

65

Te

de

Yams, F

abric

s 66

Non

-met

allic

Min

erd

Man

ufac

ture

s 67

Iron

ands

teel

68

Non

-ferr

ous

Met

als

6g

Man

ufac

ture

s of M

etal

, n.e

.s.

71

Mac

hine

ry, n

ot E

ktri

cal

72

Ele

ctri

calM

achi

iery

73

Tra

nspo

rt E

quip

men

t

07

68.0

1,693'0

1,316.1

43

4453'8

21.6

1,688.1

11396.9

8,7398

427'3

46576

56.5

144.0

2771

3 87.9

05

40

4,868.9

09

17.0

148.8

01

1,711-6

1.~0

23

271'4

423'9

342.2

2198

001

40

2'0

25'0

61.2

02

492'3 7.1

E 0 z

2'2

9,775'1

291.

5 3,992'1

1.102-6

18.2

746

9.9346

169

195'4

343

1.0

449'5

285.7

78.0

63-2

1,5243

275.0

599

3,147'5

585.2

1,443

3.340'3

612.1

757'5

53'3

07

123-2

87.8

1,8896

48.3

191.4

499'8

455'4

390'5

68.9

92.2

12,037.2

1246

221'2

84

4

SITC

Div

ision

Ar

gent

ina

Braz

il Ch

ile

Colo

mbi

a Ec

uado

r M

exic

o Pa

ragu

ay

Pen4

81

Plum

bing

, Hea

ting

Fixt

ures

73

.6

83

Tra

vel G

oods

0

1

85

Foot

wea

r 3 140

86

Phot

o, O

ptic

al S

cien

tific

Inst

rum

ents

94

2'4

206.0

1.8

89

Mis

cella

neou

s Man

ufac

ture

s, n.

e.s.

3

,01

2'3

53

41

39'3

82

Furn

iture

32

.1

84

Clo

thin

g 2'

5 61

.0

3'6

6.3

1'1

5'2

4'

1 5S

.I

28.3

5812

0

1

246.

6 17

-9

907

02

270 JOURNAL OF COMMON MARKET STUDIES

exports. Column 5 , expressed as a percentage, indicates that for Mexico and Brazil the majority of stimulation was in non-traditional exports while the opposite was true for Peru and Argentina. Column 6 presents the value of stimulation on non-traditional exports as a percentage of total exports, and in this fashion adjusts for the size differences of the export sectors of the member countries. Ranking the percentages in Column 6 permits comparison of the progress of the members towards export diversification. For example, Argentina will rank near the top because of the high value of its export stimulation in relation to its total exports, while the respectable Mexican performance results from the large proportion of non-traditional exports involved. Conversely,

TABLE I11

Argentina Brazil Chile Colombia Ecuador Mexico Paraguay Peru

TotalEvport As% Total Stimulation Export

(thousands U.S. dollars)

36,323 36,500 12,105 4,882

3 8,077 4,250 26,397

104,929 I1 3 7 3 6 6

I3 6

Colombia shows relative weakness on both counts. Examination of Table I1 in conjunction with Table IV allows the reader to identifjr specific products which have made substantial contributions to export diversification.

Interestingly, the correspondence between traditional and stimulated exports for several countries suggests that trade creation may have been more significant than trade diversion. Assuming that traditional export patterns are basically determined through comparative advantage, an expansion of intra-regional trade in those products indicates a switching towards low cost producers and consequently represents trade creation. LAFTA proponents who reject trade creation as an evaluation criterion, and who adopt industrialization and diversification as legitimate integration objectives, implicitly recognize that trade creation and industrialization are not consistent goals in Latin American integration.

Integration may contribute to industrialization in one of two ways.

TA

BL

E

IV

EXPO

RT&

DIV

ERSI

FIC

ATI

ON

*

Non-

tradi

tiona

l In

itial

To

tal E

xpor

t Ex

port

(4

) as p

erce

ntag

e (4

) as p

erce

ntag

e Co

untr

y Co

ncen

tratio

n St

imul

atio

n St

imul

atio

n of

(3)

of To

tal E

xpor

ts

(1)

(2)

(3)

(4)

(5)

(6)

Arg

entin

a B

razi

l C

hde

Col

ombi

a Ec

uado

r M

exic

o Pa

ragu

ay

Peru

%

67

82

89

97

88

53

81

75

(thou

sand

s U.S

.

36,3

23

36,5

00

12,1

05

4,88

2 3 8

,077

4,

250

26,3

97

104,

929

%

44.3

88

.9

61.0

50

'4

53'6

80

.0

48.4

25

'4

* See

text

for e

xpla

natio

ns. D

ata

deriv

ed fr

om so

urce

s lis

ted

in A

ppen

dix.

P

m rA v) E C

272 JOURNAL O F COMMON MARKET STUDIES

It may directly expand production and export of industrial products. Alternatively it may, through expanded export earnings, increase im- port capacity, and thus assist in programs for industrialization. Progress along the first, direct, path will be made evident by examination of the composition of export stimulation as presented in Tables I and 11. Progress along the second route will be reflected in the total value of stimulation without regard to its composition, and is properly examined together with the matter of growth contribution.

Evaluation of the data contained in Tables I and I1 with respect to industrialization is facilitated by considering products to be of industrial origin if they fall within SITC Sections 5-8 (Chemicals, Manufactures by Material, Machinery and Transport, Miscellaneous Manufactures). Although the division is not totally satisfactory, excluding as it does food preparations and including items such as blister copper, it does provide a convenient basis for constructing Table V and analysing the industrialization contribution of integration.

The format of Table V is similar to Table IV. Column 2 is the percentage of total exports accounted for by SITC Sections 5-8, and thus provides an indication of the relative industrial component of LAFTA members’ exports, Column 3 repeats the total value of export stimulation and Column 4 is the value of stimulation of industrial exports. Column 5 is the percentage of total stimulation accounted for by industrial commodities and the Mexican, Brazilian and Chilean performances stand out in relation to the showing of the other members.9 Column 6 again adjusts for the different sizes of the export sectors of the members by showing stimulation of industrial products as a percentage of total exports. Disregarding the special Chilean situation, the ranking of Column 6 reveals that Mexico has garnered quite the largest share of direct industrialization benefits. Notice also that, to the extent that there is a similarity between traditional and non- industrial export product groups, there will tend to be a correspondence between the export diversification and direct industrialization benefits received by members.

The assumption of this paper has been that a positive relationship exists between the level of export earnings and the growth rate, and that an expansion of export earnings, measured by the value of export Stimulation, will enable a country to attain a higher growth rate. The relationship is at the heart of an extensive body of literature concerning foreign exchange constraints upon growth and development. It has not, however, been systematically incorporated into a formal theoretical study of integration among less developed countries, although work

9 The result for Chile may be misleading for it is due to the inclusion of unrefined copper as an industrial product.

TABLE V

IN

DU

STR

IAL

IZA

TIO

N*

Initi

al

Indu

stria

l In

dustr

ial

Com

pone

nt of

To

tal E

xpor

t Ex

port

(4) u

s pe

rcen

tage

(4) a

s per

cent

age

Coun

try

Expo

rts

Stim

ulat

ion

Stim

u Jati

on

40)

4 To

tal E

+por

ts (1)

(4

(3)

(4)

(5)

(6)

Arg

entin

a Br

azil

Chi

le

Col

ombi

a Ec

uado

r M

exic

o P

WP

Y

Peru

4 3 73t 2 3 15

15

3I$

(thousands o

f U.S.

dolla

rs)

104,929

15,528

36,323

17,357

36,501

32,402

12,105

4.934

4,882

503

3 8,077

22

,50

0

4.250

176

26,397

1,926

148

478

88.7

40 8

103

59.1

41

7'3

1-6

1 '4

6.4

06

3'5

05

0.4

1'1

5

b

I;; wl

wl c 0

0

* See te

xt fo

r ex

plan

atio

n. D

ata

deri

ved

from

sour

ces l

isted

in A

ppen

dix.

t 6

if SITC 68 is

exc

lude

d.

$ 3

if SITC 68 is

exc

lude

d.

274 JOURNAL OF C O M M O N MARKET STUDIES

along these lines has been done by Bhambri and Linder.10 The validity of this view cannot be tested here. We simply note that many of the arguments which favor the creation and strengthening of LAFTA are in fundamental harmony with, and supportive of, this view. In particular, it has frequently been advanced that the necessity for regional integra- tion derives from adverse markets for traditional exports in developed countries in conjunction with high import requirements for growth, and in this fashion export levels and growth rates are joined.

Accepting this view we conclude that the value of export stimulation not only provides an index of export expansion, but is also a measure of the relative growth contribution secured by the member countries. In consequence, the data in Table 111 can be used to rank countries along this dimension. The appropriate ranking will, of course, be drawn fiom Column 2, where size differentials among members have been adjusted for.

The range of stimulation is considerable, from 3 per cent of exports for Colombia and Brazil to 13 per cent of exports for Paraguay. More striking, however, is the absence of a clear relation between the growth contribution ranking and either a ranking of the members by level of income or a ranking by level of industrialization. Specifically, the ranking of the data in Table 111 does not support the conclusion that either the larger (Mexico, Argentina, Brazil) or the more industrialized countries (Argentina, Mexico, Chile) have gained disproportionately.

The concept of reciprocity acquires central importance in understand- ing the political process of integration. All observers have stressed that continued momentum towards integration requires some reasonable equality in the distribution of gains within the region. The problem is complicated, however. On the one hand initial differences between countries practically guarantee that reciprocity will not be automatically forthcoming, and on the other hand the several policies for achieving reciprocity such as intra-regional transfer payments, differential rates of tariff reductions, and regional allocation of industries, will have different impacts on the pace and structure of integration.

The data developed here suggest that during the time span covered by the investigation strict reciprocity was an elusive goal. It does indicate, however, that by viewing the development contribution of integration in a multi-dimensional framework of growth, industrializa- tion and export diversification, the observed pattern of reciprocity shows considerably less dispersion than otherwise might have been expected.

10 R. S. Bhmbri, ’Customs Unions and Underdeveloped Countries’, Economia Internazionale. Vol. XV (May 1962), p. 235, and S.B. Linder, ‘Customs Unions andEconomicDevelopment’, in Migucl S. Wionczek (ed.), Latin American Ecotiomic Infegrntion (New York, Praeger, 1966).

INTEGRATION A M O N G LESS DEVELOPED C O U N T R I E S

APPENDIX: Data Sources

Asociacion Latinoamericana de Libre Comercio, Serie Estadistica No. 2, Comercio Exterior Argentina: Exportacion 1961-1964.

Republica Argentina, Secretaria de Estado de Hacienda, Direccion Nacional de Estadistica y Censos, Comercio Exterior, 1966, Tomo III, and Comercio Exterior, 1967, Tomo II.

Brazil, Ministerio da Fazenda, Servicio do Estatistica Economica e Financeria, Foreign Trade OfBrazil According to the SZTC, Rio de Janeiro, for the years: 1960, 1961, 1966, 1967.

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Chile, Direccion de Estadistica y Censos, Comercio Exterior, An0 1961, Santiago. Chile, Camara de Comercio de Santiago de Chile, Comercio Exterior, 1966. Colombia, Departamento Administrativo Nacional de Estadistica, Anuario de Comercio

Exterior, for 1960 and 1961. Asociacion Colombiana de Exportadores, Analisis de Exportaciones Colombianus, 1963-

1967, Bogota, 1968. Ecuador, Junta Naciond de Planhation y Coordination, Division de Estadistica y

Censos, Anuario de Comercio Exterior 1965, Volrrmen 11, Quito. Ecuador, Ministerio de Industrias y Comercio, Comercio Exterior 1964. Ecuador, Ministerio de Industrias y Comercio, Comercio Exterior con ALALC 1957-

1963. Ecuador, Ministerio de Industria y Comercio, Comercio Exterior del Ecuador con 10s

Paises de la Asociucion Latinoamericana a% Libre Comercio (ALALC) 1962-1964. Mexico, Secretaria de Industria y Comercio, Direccion General de Estadistica,

Anuario Btadistico del Comercio Exterior de 10s Estados Unidos Mexicanos, for the years: 1960, 1961, 1966, 1967.

Banco Central del Paraguay, Departamento de Estudios Economicos, Boletin Bfadistico Mmsual, Asuncion, 1968.

Peru, Ministerio de Hacienda y Comercio, Departamento de Estadistica, Estadistica del Comercio Exterior, Lima, for the years: 1961, 1962.

Peru, Superintendencia Nacional de Aduanas, Estadistica del Comercio Exterior 1966. OECD, Commodity Trade Analysis, Series B, various issues.