Popularization of Classical Economics:
The text-mining Analysis of David Ricardo,
James Mill, and Harriet Martineau
Hiroyuki Shimodairai
Shinji Fukudaii
Research Group of Economics and Management
No. 2014-E01
2014.12i

Faculty of Literature and Social Sciences, Yamagata University, E-mail: shimo [at]human.yamagata-u.ac.jp
ii Fuculty of Humanities, Hirosaki University, E-mail: shinji [at] cc.hirosaki-u.ac.jp

Popularization of Classical Economics:
The text-mining Analysis of David Ricardo, James Mill, and Harriet Martineau
Hiroyuki Shimodaira & Shinji Fukuda
1 Introduction
1.1 The background of the study
Ricardo’s Principles of Political Economy (1st ed., 1817) established the theoretical foundationsof classical economics and determined the direction of the later history of economics. However,Ricardo’s Principles was not necessarily accepted directly into society at large. It is wellestablished that certain individuals --- including James Mill and Harriet Martineau, who was not a
top class theorist in the field --- played an important role in the dissemination of Ricardian
economics. In other words, classical economics spread throughout over the general public by wayof popular textbooks or enlightenment works such as Mill’s Elements of Political Economy (1sted., 1821) and Martineau’s Illustrations of Political Economy (9 vols., 1st ed., 1832-34), as well as
through technical books such as Ricardo’s Principles. Therefore, due to the mechanisms ofdiffusion, not only are there problems regarding the technical content of economics, but these
problems are magnified and transformed into popular beliefs. Certainly, this has been widespread
issue found in the overall history of economics. 1
If we consider such circumstances, we must examine more popular literature as well as
specialized discourse in order to study the general process of dissemination of economics. It is
expected that such literature will amount to enormous quantities. Even the principal technicalbooks throughout the history of economic thought are greatly numbered, and it is difficult to evenelucidate those contents. Therefore, in order to examine the enormous body of more popularliterature in addition to detailed scholarly works, a method distinct from the conventional
qualitative study of economic literature is needed to fulfill this investigation of the history of
economic thought. In this paper, we propose text-mining analysis as a means to investigate thisquestion. Text-mining analysis is a technique that enables us to statistically process the text data ofvarious literatures and to examine such literature quantitatively. The following section will outline
this process in further detail. In this paper, we will investigate whether such analysis is effective inthe study of the history of economic thought while focusing on the process of the dissemination ofclassical economics.
In addition, this paper is associated with the the project, ‘A proof study of the process ofreception and spread of economic thought: How did people receive economics?’ 2 This project is
an attempt to qualitatively and quantitatively categorise the process by which economic theory andthought have disseminated from economic specialists to non-specialists, that is, the general public,
through the last 200 years beginning with the formation of classical economics, while focusing the-1-research on the history of economic thought in England. Our primary approach attempts to clarify
the process underwent by the theories and thoughts in the representative literatures of economics(Adam Smith’s Wealth of Nations, Karl Marx’s Capital, John Maynard Keynes’ General Theory,
among others) as they were accepted into the general public through more popular criticisms,
primers, textbooks, commentary books, popularity books, poetry, fables, novels, brochures, andhandbills, among others.
1.2 The task of this paper
The task of this paper is to examine the process of dissemination of classical economics througha text-mining analysis of major works, as a part of the project mentioned above. In particular, we
will clarify some aspects of the process of popularization of Ricardian economics. For this purpose,
we will examine Ricardo’s Principles (3rd ed.), Mill’s Elements (3rd ed.), and Martineau’s
Illustrations, No.25 (3rd ed.), and compare them, using the text-mining analysis procedure.
Martineau is known for her important role in the dissemination of classical economics; mostnotably, Ricardo’s arguments in his Principles were spread into the general public by Martineau’s
works, Illustrations. What kind of transformation did Ricardian theory undergo at this time? We
seek to clarify that process while referring to Mill’s Elements. With these three formative works,
we aim to investigate the validity of using a text-mining analysis to study of the process by which
economics is disseminated.
Because Martineau assumed that her audience in Illustrations would be the general public, inthis paper we set the following two hypotheses;(1) Martineau removes technical terms, and uses a many popular words easily understood by thegeneral public.
(2) In contrast with Ricardo and Mill, Martineau contextualizes the discourse with real world
policies and maintains a broader worldview in the background rather than simply relying on
basic theory analysis.
In the following sections, we investigate whether such hypotheses are recognized as appropriate,
and whether they are supported by the text-mining analysis.
2 The outline of the text-mining analysis and the text data
2.1 The study of history of economic thought and the text-mining analysis
The text-mining analysis is ‘a generic name of the various technique to analyse text data
quantitatively with the calculator and to extract a useful law’ (Matsumura & Miura 2009: 1).
Originally, ‘mining’ refers to the act of ‘digging out coal’. Therefore, the text-mining analysis
includes two basic characteristics. The first is to extract a law or knowledge hidden in a large
quantity of information. The second is to carefully select the meaningful, important, and usefullaws from the various extracted information. At the first stage, we use mathematic processing-2-

(quantitative analysis), mainly employing a statistics processing software. However, at the second
stage, we must make a judgment in order to select what is not self-evident, but what is meaningful,in regards to laws, interpretations, and knowledge; that is, we implement a qualitative analysis. In
other words, the text-mining analysis provides a quantitative perspective to supplement thequalitative analysis.
Therefore, the text-mining analysis creates the possibility to connect with a conventional methodof the study of the history of economic thought. In the text-mining analysis, we first collect thedigitized data of the literature, then adjust the data for statistical processing, process the adjusted
data, and obtain a result. However, the text-mining analysis is not concluded with this technicalprocessing only. We must provide our ‘interpretation’ at every stages; that is, when regarding the
hypothesis, the meaning of the collected data, the naming of categories, the significance of theresults and their limits, and when considering the importance placed upon the process in general.
For this reason, the text-mining analysis absolutely requires the knowledge of previous studies of
the history of economic thought, which have been accumulated throughout many years. In applying
this prior knowledge, we may discover new knowledge, for example, the identification of thewriter of an anonymously authored work, clarification of changes in different editions of a book,and the transformation of popularized verbal explanation that has been previously unnoticed. These
discoveries are made possible through statistically processing a large quantity of the text data in theliterature.
In other words, we expect to find more general and more persuasive knowledge by applying thequantitative statistical analysis to a large amount of text data than that provided by individual
example report using a qualitative analysis to examine a smaller body of work. In this sense, thetext-mining analysis is completely compatible with the traditional methods used to study thehistory of economic thought; it may establish itself as a new method to study of the history of
economic thought that further develops the field, bringing about a more heuristic knowledge of thesubject. 3
2.2 The outline of the text-mining analysis
In this paper, we will compare and contrast Ricardo’s Principles, Mill’s Elements, andMartineau’s Illustrations, No.25, using frequency analysis and co-occurrence network analysis,
which form the representative techniques of the text-mining analysis. Before the analysis, weoutline the process of these techniques in detail. In this study, we use the KH Coder 4 as the
text-mining software in these analyses.
(1) The frequency analysis
The frequency analysis examines the frequency of certain words in the analysed literature. In
this paper, we extract nouns that appear to be highly frequent in the literature using the KH Coder.
We focus our attention on nouns in this paper based on a proposition of the categorization study incognitive psychology; that is, ‘it is nothing but in noun that a certain idea, concept, and thought
appear most symbolically’ (Kida 2008: 151). At its core, the frequency analysis reflects a basic-3-

logic that ‘a word of higher frequency of appearance is higher in importance’ and ‘a word of lower
frequency is lower in importance’; these assumptions allow us to characterize the selected
literature.
(2) The co-occurrence network analysis
The co-occurrence network analysis seeks to examine the relationship between various words inthe literature. When we are not able to sufficiently clarify the characteristics of the literature byusing the frequency analysis, we may provide further clarification through as examination of therelationship between the words in the literature by using the co-occurrence network analysis. Using
the KH Coder, we will be able to elucidate a relationship between the words, by connecting words
that have similar pattern of appearance with line. This indicates a strong degree of co-occurrence,
and allows us to further visualise these relationship by drawing a figure showing the network of
those lines.
Regarding the relative strength of the co-occurrence, we can find the value of the Jaccard
coefficient that is calculated with respect to all combinations of the words in the literature. The
Jaccard coefficient takes a value between 0 and 1; as the frequency of two words appearing(co-occuring) in the same sentence increase, the value becomes closer to 1. If the two words do notappear (do not co-occur) in the same sentence, the value is closer to 0. The Jaccard coefficient (J)of the co-occurrence between any word X and any word Y is calculated in the following equation:
J=A/(A+B+C)
Here, A expresses the number of the sentences where both word X and word Y appear at the sametime, B expresses the number of the sentence where only word X appears, and C expresses thenumber of the sentence where only word Y appears.
The KH Coder automatically calculates the value of the Jaccard coefficient, and draws a figure
displaying the network between the words. Concerning the network figure form, we can choose
one of two patterns of figures: (1) a network based on the ‘centricity’ of the words, and (2) a
network introduced by the ‘sub-graph detection’. These figures are used in order to identify
commonalities among the various literature studied. 5(1) Centricity analysis: With this analysis, the network figure shows the extent which each word
plays a central role in the literature. Each word is distinguished by colour; their degree of thecentricity is shown in order of red, pink, white, light blue, with red showing the greatest.
(2) Sub-graph detection: This analysis reveals words that are strongly tied to one another in theliterature, and the network figure displays groups of these words. Each group is distinguishedby colour: green, yellow, blue, red and so on. 6 A white colour indicates that it is anindependent word that does not form a group with other words. A solid line connects words
included in the same group; words included in different groups are connected by a broken
line.
In addition, words with stronger co-occurrence are connected by a thicker line in both network-4-

figures.
2.3 The text data of the literature
For our text-mining analysis, we use the text data from the sources listed below: 7
Ricardo, D. 1821, The Principles of Political Economy, and Taxation, 3rd ed., London: John
Murray.
Mill, J. 1844, Elements of Political Economy, 3rd ed., London: Henry G. Bohn.
Martineau, H. 1834, Illustrations of Political Economy, 3rd ed., vol.9, London: Charles Fox.
We digitize each of the text data of these literatures according to the following procedure:(1) Scan the text data and process it with the Optical Character Reader (OCR).
(2) Shape the data by manually correcting a mistaken data and removing a meaningless signs
using software such as Microsoft Word.
(3) Give these data a tag and save it as a text file.
After this process, we analyse the digitized data using the KH Coder.
3 The results of the analysis
3.1 The frequency analysis
We first applied the frequency analysis to Ricardo’s Principles, Mill’s Elements, andMartineau’s Illustrations, No.25, and extracted the nouns that rank from 1 to 30 in frequency of
appearance in each document; results are displayed in Table 1. 8 Thus, we are able to clarify thefollowing points in comparing the highest ranking nouns in each document:(1) The ten highest-ranking nouns (indicated in red) in Ricardo’s Principles are included in all of
the 30 highest-ranking nouns in Mill’s Elements, but only five nouns among them are found in
the top 30 ranking nouns in Martineau’s Illustrations, No.25.
(2) Among the nouns ranked 11-20 in Ricardo’s Principles, nine of these are included in the 30
highest-ranking nouns in Mill’s Elements, but only six nouns are found among those in
Martineau’s Illustrations, No.25.
(3) Among the nouns ranked 21-30 in Ricardo’s Principles, only two of these are included in the
30 highest-ranking nouns in Mill’s Elements or Martineau’s Illustrations, No.25.
(4) In the 30 highest-ranking nouns in Mill’s Elements, nines nouns are found that do not appear
in the 30 ranking of nouns in Ricardo’s Principles. Furthermore, only three words of thesewords appear in the 30 highest-ranking nouns in of Martineau’s Illustrations, No.25.
(5) In the 30 highest-ranking nouns in Martineau’s Illustrations, No.25, 14 of these (indicated inblue) are not found in the 30 highest-ranking nouns in either Ricardo’s Principles or Mill’s-5-Elements.
3.2 The co-occurrence network analysis (1): the centricity analysis
Next, we applied the co-occurrence network analysis to the nouns in Ricardo’s Principles, Mill’s
Elements, and Martineau’s Illustrations, No.25, and drew figures of the network based on their‘centricity’; these are expressed in Figures 1.1-1.3. 9 We then made the following observations
based on a comparison of these figures:(1) In Ricardo’s Principles, ‘price’ and ‘profit’ play the most central role, with ‘produce’ and‘labor’ being of secondary importance.
(2) In Mill’s Elements, ‘labor’ and ‘commodity’ play the most central role, with ‘wages’,‘capital’, and ‘money’ having secondary importance.
(3) In Martineau’s Illustrations, No.25, ‘capital’ and ‘society’ play the most central role.
(4) The most centrally important nouns among the three texts are all different from each other.
3.3 The co-occurrence network analysis (2): the sub-graph detection
Lastly, we drew the figures of the network by applying the ‘sub-graph detection’ to Ricardo’s
Principles, Mill’s Elements, and Martineau’s Illustrations, No.25; these are presented in Figures
2.1-2.3. A comparison of these figures enabled the following observations:(1) In Ricardo’s Principles, the first group (in green) includes ‘money’, ‘value’ and ‘corn’, et al.,the second group (in yellow) includes ‘land’, ‘produce’, and ‘rent’, et al., and the others arefound.
(2) In Mill’s Elements, the first group (in green) includes ‘proportion’, ‘case’, and ‘labourer’ etal., the second group (in yellow) includes ‘price’, ‘commodity’, and ‘quantity’, et al., and theothers are found.
(3) In Martineau’s Illustrations, No.25, the first group (in green) includes ‘labourer’, ‘capitalist’,and ‘wages’, et al., the second group (in red) includes ‘country’, ‘commodity’, and ‘money’,
et al., the third group (in blue) includes ‘food’, ‘supply’, and ‘demand’, et al., and the others
are found. In addition, the groups are more decentralized and further divided in comparison
with the previous two works.
(4) In the first group of Ricardo’s Principles, the second group of Mill’s Elements, and thesecond group of Martineau’s Illustrations, No.25, the components that are common among
two or three of the texts, such as ‘money’ and ‘commodity’, among others, are found, but theirconstruction within the chart differ greatly from one another.
(5) In the second group of Ricardo’s Principles, the first group of Mill’s Elements, and the firstgroup of Martineau’s Illustrations, No.25, words such as ‘produce’ and ‘labourer’ are found in
two of the groups, but these do not appear among all three network.

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4 Considerations
4.1 The characteristics of Ricardo’s Principles
In his Principles, Ricardo examined theoretical and policy issues in relation to value,
distribution, growth, trade, tax, and money, based on his labour theory of value.
First, according to the frequency analysis in Table 1, the ten highest-ranking nouns in Ricardo’s
Principles are ‘price’, ‘value’, ‘commodity’, ‘labor’, ‘capital’, ‘quantity’, ‘profit’, ‘tax’, ‘corn’, and‘money’. This result reflects the arguments made in Ricardo’s Principles. It is important to notethat the frequency of highest ranking noun, ‘price’, and the second-highest ranking noun, ‘value’,greatly surpasses the others; this suggests that Ricardo placed a greater importance on the issue of
determining price or value. In addition, the concepts such as ‘rent’ and ‘wages’, which are of great
importance to Ricardo, are found in the nouns ranking 11-20 in the table. Although the focus seems
to dim slightly, important concepts such as ‘gold’ and ‘trade’ are also found in the ranking ofnouns from 21-30.
Next, based on the centricity analysis of the co-occurrence of words in Figure 1.1, we observethat ‘price’ and ‘profit’ play the most central role in Ricardo’s Principles, and ‘produce’ and‘labor’ play a slightly less crucial role. This result is reminiscent of Ricardo’s arguments in his
Principles concerning the relation between the decision of price and the falling rate of profits.
Moreover, according to Figure 2.1 of the sub-graph detection of the co-occurrence network
analysis, the first group of nouns (in green) in Ricardo’s Principles consists of ‘money’, ‘value’,‘corn’, ‘commodity’, ‘quantity’, ‘production’, ‘labor’, and ‘price’. This group primarily reflects
Ricardo’s arguments on the labour theory of value and the changing of corn prices in his
Principles. In addition, the second group (in yellow) consists of ‘land’, ‘produce’, ‘rent’, ‘profit’,‘tax’, and ‘landlord’. This group mainly reflects Ricardo’s arguments on the distribution andtaxation in his Principles.
In this way, the results of the text-mining analysis appropriately, although roughly, illustrate
defining characteristics of Ricardo’s Principles.
4.2 The characteristics of Mill’s Elements
Mill, known to be a friend of Ricardo, pressed Ricardo to write his Principles. Mill subsequently
organized his own notes on the subject in order to teach his son, John Stuart Mill, the elements ofRicardo’s Principles, and wrote his Elements as an introduction to Ricardian economics. In his
Elements, Mill explains the principles of Ricardian economics while dividing them into the four
branches: production, distribution, exchange, and consumption.
According to the frequency analysis in Table 1, the ten highest-ranking nouns in Ricardo’s
Principles are all included in 30 highest-ranking nouns in Mill’s Elements, and nine nouns among
those ranked 11-20 in Ricardo’s Principles are included in 30 highest-ranking nouns in Mill’s
Elements. These results reflect the fact that Mill’s Elements is relatively faithful to Ricardo’s
Principles. However, the highest ranking word in Ricardo’s Principles, ‘price’, drops down to rank

-7-

16th in Mill’s Elements; similarly, the ninth-ranking word, ‘corn’, drops down the rank 23rd.
Additionally, only two nouns among those ranked 21-30 in Ricardo’s Principles are found in thehighest 30 in Mill’s Elements, and concepts such as ‘gold’ and ‘trade’, which were deemed asimportant to Ricardo, are not included at all. These results suggest that the central arguments in
Ricardo’s Principles were slightly diluted in Mill’s Elements.
Next, according to Figure 1.2 displaying the centricity analysis of the co-occurrence network,‘labor’ and ‘commodity’ play the most central role in Mill’s Elements, and ‘wages’, ‘capital’, and‘money’ play a subordinate, although still important, role. This result suggests that the central
arguments in Ricardo’s Principles do not necessarily occupy an identical position in Mill’s
Elements.
Moreover, according to the sub-graph detection of the co-occurrence network analysis in Figure
2.2, the first group of nouns (in green) in Mill’s Elements consists of ‘proportion’, ‘case’,‘labourer’, ‘wages’, ‘profit’, ‘labor’, ‘capital’, ‘portion’, ‘rent’, ‘produce’, and ‘land’. This group
includes the components that are common to the second group of Ricardo’s Principles (listed here
in italics), so it shows correspondence, to some extent, with the latter. In addition, the second groupof nouns (in yellow) in Mill’s Elements consists of ‘price’, ‘commodity’, ‘country’, ‘quantity’,‘money’, ‘value’, and ‘metal’. This group includes the components (in italics) that are common to
the first group of Ricardo’s Principles, again showing a degree of correspondence to the latter.
These results further demonstrate that Mill’s Elements follows Ricardo’s Principles fairly
consistently. However, in Mill’s Elements, a small group of nouns (in orange, red, purple, andblue), which are not observed in Ricardo’s Principles, is found. It is particularly interesting to notethat the appearance of the small group consisting of ‘supply’ and ‘demand’ is found. These results
suggest that the construction of economic arguments is more decentralized in Mill’s Elements thanin Ricardo’s Principles.
In this way, the results of the text-mining analysis show that Mill’s Elements follows Ricardo’s
Principles in a relatively faithful manner. At the same time, the construction of the arguments
relating to the labour theory of value and the decision of corn prices, elements inherent to
Ricardo’s Principles, is somewhat diluted in Mill’s Elements.
4.3 The characteristics of Martineau’s Illustrations, No.25
Martineau played a particularly important role in the dissemination of classical economics.
Martineau drew the various morals derived from the principles of classical economics and rewrote
them in a fable style so that the general public would easily understand them. This is presented in
her Illustrations, which consists of nine volumes containing 25 fables. In the fable, No.25,
Martineau showcases the principles of economics that form the theoretical bases for fables,
Nos.1-24. Here, Martineau relies on the construction of the four branches of economics from Mill’s
Elements. 10
First, according to Table 1 showing the frequency analysis, only five nouns among the tenhighest-ranking nouns in Ricardo’s Principles (specifically, ‘value’, ‘commodity’, ‘labor’,‘capital’, and ‘money’) are included in the top 30 in Martineau’s Illustrations, and the other five-8-

nouns (‘price’, ‘quantity’, ‘profit’, ‘tax’ and ‘corn’) are not included; of particular note is theabsence of the highest-ranking nouns in Ricardo’s Principles, ‘price’. Nouns which do appear inboth Ricardo’s Principles and Martineau’s Illustrations, No.25, see a large decrease in rank in thelatter text; for example, ‘value’, which is the 2nd most frequent noun in Ricardo’s Principles, drops
down the rank the 21st in Martineau’s Illustrations, No.25. In place of these nouns, ‘labor’ becomes
the highest-ranking noun, followed by ‘capital’. Moreover, only six nouns among those ranked
11-20 in Ricardo’s Principles are included in the top 30 most frequent nouns in Martineau’s
Illustrations, No.25, and only two nouns among those ranked 21-30 in Ricardo’s Principles appear
in the ranking of Illustarations, No.25. On the other hand, 14 nouns not included in 30 mostfrequent nouns in either Ricardo’s Principles or Mill’s Elements are found in Martineau’s
Illustrations, No.25. Particularly, nouns such as ‘society’, ‘principle’, and ‘class’ are included.
These results indicate that the central arguments based on the labour theory of value in Ricardo’s
Principles are greatly diluted in Martineau’s Illustrations, No.25.
Next, according to the centricity analysis on the co-occurrence network in Figure 1.3, ‘capital’and ‘society’ play the most central role in Martineau’s Illustrations, No.25. This result reinforces
the suggestion that the central arguments in Ricardo’s Principles do not occupy the same
fundamental position in Martineau’s Illustrations, No.25.
Moreover, according to Figure 2.3 displaying the sub-graph detection of the co-occurrence
network analysis, the first group of nouns (in green) in Martineau’s Illustrations, No.25, consists of‘labourer’, ‘capitalist’, ‘population’, ‘wages’, ‘capital’, ‘labor’, and ‘proportion’. This group
includes the components (in italics) that are common to the first group of Mill’s Elements, thus
some level of correspondence with the latter in observed. In addition, the second group of nouns(in red) in Martineau’s Illustrations, No.25, consists of ‘commodity’, ‘country’, ‘money’, and‘place’. This group includes the components (in italics) that are common to the second group ofMill’s Elements, again showing correspondence, to some extent, with the latter. Furthermore, thethird group of nouns (in blue) in Martineau’s Illustrations, No.25, consists of ‘food’, ‘supply’,‘demand’, and ‘production’. This group corresponds to the small group consisting of ‘supply’ and‘demand’ in Mill’s Elements. These results reflect that Martineau’s Illustrations, No.25, has aconstruction of arguments that is relatively analogous to Mill’s Elements. That being said, manysmall groups (in yellow, green, pink, purple, gray, and orange) are seen in Martineau’s
Illustrations, No.25, more often than in Mill’s Elements. These results suggest a further
decentralization in the construction of arguments in Martineau’s Illustrations, No.25, more so thanin Mill’s Elements.
In this way, the results of the text-mining analysis show that, although Martineau’s Illustrations,No.25, is to some extent, similar to Mill’s Elements, the central concepts and the construction of
the arguments differ greatly. In Martineau’s Illustrations, No.25, the construction of the argumentswith respect to the labour theory of value and the decision of corn prices --- which are crucialcomponents in Ricardo’s Principles --- is further diluted, and in place of these, the relation between
capital and labour, or the problem of class, moves to occupy the central positions in the work.

-9-5 Concluding remarks
5.1 Summary
In this paper, we have clarified the differences of the construction of arguments between
Ricardo’s Principles, Mill’s Elements, and Martineau’s Illustrations, No.25, by applying thetext-mining analysis to those works. According to the results of the frequency analysis, the mostfrequent nouns in Ricardo’s Principles drop down in rank in Mill’s Elements; this pattern isadvanced in Martineau’s Illustrations, No.25, with nouns dropping down even further in rank, andin their place, other nouns occupy these high-ranking positions. Most of the nouns that see adecrease in rank correspond to the theoretical concepts regarding the decision of price and the
distribution of income; most of nouns that rise in the rank correspond to realistic concepts used toexpress roughly a view of society. According to the co-occurrence network analysis, the nouns thatplay central roles in Ricardo’s Principles are replaced by other nouns in Mill’s Elements; thosenouns are replaced yet again by other nouns in Martineau’s Illustration, No.25. At this point, thenouns that correspond to the theoretical concepts concerning the decision of price and the
distribution of income are gradually derived their roles by the nouns that correspond to the realistic
concepts used to express roughly views of society. Additionally, the groups of the nouns that areconnected to each other in Ricardo’s Principles are, to some extent, maintained in Mill’s Elements,
although they exhibit slight changes; those groups are altered and greatly decentralized in
Martineau’s Illustrations, No.25. As a result, arguments constructed through strict theoreticalconcepts are decentralized and gradually popularized. The outcome of these considerations is seenin the process by which the specialized arguments in Ricardo’s Principles were progressively
simplified in Mill’s Elements and decisively popularized in Martineau’s Illustrations; in this way,
Ricardian economics broadly spread out to the general public.
Therefore, the hypothesis proposed in the beginning of this paper is justified; that is, because
Martineau assumed the general public as a reader of her Illustrations, (1) she removes technicalterms and uses many popular words easily understood by the general public, and (2) she grounds
her discussion in real world policies and broader worldview, rather than simply discussing basic
theoretical analysis, in contrast with Ricardo and Mill. This paper demonstrates that such
hypotheses were supported by the text- mining analysis.
5.2 Problems left unfinished
While the aforementioned hypotheses are supported by the text-mining analysis, they are notdefinitely proved solely based on this technique. Needless to say, we must examine the text data
not only quantitatively, but also qualitatively, in order to sufficiently prove such hypotheses. 11 As
previously mentioned, the text-mining analysis only provides a quantitative measure to supplement
a qualitative analysis. In this sense, we have not yet fully elucidated the process of thedissemination of classical economics, and the text-mining analysis remains incomplete. Due tolimits on the scope of this paper, we must leave this task to future investigations.

- 10 -Despite these limitations, this study clarified certain aspects concerning the process ofdissemination of classical economics, and demonstrated the suitability of text-mining analysis instudying the history of economic thought. This paper is a trial of text-mining analysis on theprocess of dissemination of classical economics and a preparation for further full-scale text-mining
analysis.
[Acknowledgements] This work is supported by JSPS Grant-in-Aid for Scientific Research (B),
Grant Number 22330064.

Notes1) Such a problem is closely related to the problems studied by certain scholars as the‘institutionalization of economics’ or the ‘history of economic policy thought’. Particularly
important studies include the following: Coats (1981); Coats (1993); Furner & Supple (1990);
Ikeo (2006); Nishizawa, Hattori & Kurita (1999).
2) The Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B),
Grant Number: 22330064, Research Term: 2010-2014, Leader: Hiroyuki Shimodaira(Yamagata University), Partakers: Tatsuro Kanai (Tohoku Institute of Technology), Atsushi
Komine (Ryukoku University), Shinji Fukuda (Hirosaki University), Keiko Funaki (Musashi
University), Yutaka Furuya (Tohoku University), Ryo Hongo (Kansei Gakuin University),
Naoki Matsuyama (University of Hyogo).
3) Refer to Shimodaira, Komine & Matsuyama (2012), Section 1, for the problems encounteredwhen applying text-mining analysis to the study of the history of economic thought.
4) The KH Coder is a free software used for the text-mining analysis that can investigate thecharacteristics of the text data by extracting and aggregating words from those data. It can be
downloaded online from the site (http://khc.sourceforge.net/). Refer to Higuchi (2012) for
usage instructions.
5) The figure in the network of the centricity analysis is drawn based on ‘mediation centricity’,and the figure of the network of the ‘sub-graph detection’ is drawn using the ‘method basedon the mediation of the co-occurrence relationship’ (Higuchi 2012: 63).
6) The colour of the group of words is determined by automatic processing in the KH Coder, so
the colour has no inherent importance. Therefore, it is desirable that we do not rely too
heavily on this classification but instead use it to assist the interpretation of the figure of the
network (Higuchi 2012: 62).
7) We can also download the digitized text data of the literature from the website ‘The Online
Library of Liberty’ (http://oll.libertyfund.org/). However, these data have some faults; forexample, the pages of the original works are not indicated.
8) In the process of counting the frequency of appearance, the plural forms of the nouns are- 11 -

transformed into the singular forms and are counted with the singular forms by automatic
processing of the KH Coder. In addition, the British spellings are transformed into the U.S.
spellings automatically; for example, ‘labour’ is transformed into ‘labor’. Because suchadjustments are made automatically, we must not give the result of the analysis an excessively
precise interpretation.
9) We can confirm the numerical value of the Jaccard coefficient of each word by using thecommand ‘the search for the related words’ of the KH Coder. For example, the ranking (the1-10) of the value of the Jaccard coefficient between the highest ranking noun of frequency,‘price’, and the other nouns in Ricardo’s Principles are indicated in the table below.
The ranking of the Jaccard coefficient of the noun ‘price’ in Ricardo’s Principles
Rank

Extracted Word

Whole

Co-occurrence

Jaccard Coefficient

1

Commodity

592

264

0.2435

2

corn

411

214

0.22463

profit452

171

0.1649

4

money

369

157

0.1622

5

wages

323

136

0.14426

produce366

1410.1437

7

rise

206

119

0.1412

8

labor

514

156

0.1400

9

tax

410

133

0.128810

quantity450

132

0.1229Here, the colum ‘whole’ expresses the number of the sentences in which the noun appears,
and the ‘co-occurrence’ expresses the number of the sentence in which ‘price’ and the noun
appear together. Based on such numerical values, the figure of the network of the ‘centricity’and the figure of the network by the ‘sub-graph detection’ are drawn. Refer to Higuchi (2012:49-52) for a detailed account of the command ‘the search for the related words’.
10) Refer to Funaki (2006), Sakurai (2003), and Uemiya (1996) for details on the influence ofMartineau's Illustrations.
11) We can connect the quantitative analysis of the text data to the qualitative analysis by using
the command ‘the KWIC concordance’ of the KH Coder. We are then able to investigate thequalitative context of the role played by the extracted words in the literature. Refer to Higuchi(2012: 44-49) for the details of that command.

- 12 -

References
Coats, A.W. (ed.) 1981, Economists in Government: An International Comparative Study,
Durham: Duke University Press.
Coats, A.W. 1993, The Sociology and Professionalization of Economics, London & New York:
Routledge.
Furner, M.O. & Supple, B. (eds.) 1990, The State and Economic Knowledge: The American andBritish Experiences, Cambridge: Cambridge University Press.
Martineau, H. 1932-34, Illustrations of Political Economy, 9 vols., London: Charles Fox.
Mill, J. 1821, Elements of Political Economy, London: Printed for Baldwin, Cradock and Joy.
Ricardo, D., Sraffa, P. (ed.) 1951-73, The Works and Correspondence of David Ricardo, 11
vols., Cambridge: Cambridge University Press.
(Japanese)
Funaki, K. 2006, Evaluation of Illustrations of Political Economy by Harriet Martineau in the
History of Economic Thought, Journal of Musashi University Research Center, 16: 151-69.
Higuchi, K. 2012, Reference Manual for the KH Coder 2.x (http://khc.sourceforge.net/).
Ikeo, A. 2006, Economics in Japan: The Internationalization of Economics in the TwentiethCentury, Nagoya: Nagoya University Press.
Kida, M. 2008, How to Use the Text Mining, Tokyo: Hakuto Shobo.
Jin, M. 2009, Introduction to the Statistical Science of Text Data, Tokyo: Iwanami Shoten.
Muramatsu, N. & Miura, A. 2009, Text Mining for Humanities and Social Sciences, Tokyo:
Seishin Shobo.
Nishizawa, T., Hattori, M. & Kurita, K. (eds.) 1999, History of Economic Policy Thought,
Tokyo: Yuhikaku.
Shimodaira, H., Komine, A. & Matsuyama, N. 2012, An Introduction to Text Mining for theHistory of Economic Thought: Keynes’s General Theory and its Book Reviews, Discussion
Paper Series: Research Group of Economics and Management, No.2012-E02, Yamagata
University.
Sakurai, T. 2003, Appearance of H. Martineau’s Illustration of Political Economy, Journal ofMusashi University, 50 (2): 201-63.
Uemiya, S. 1996, On H. Martineau’s Political Economy, Journal of Political Economy andCommercial Science, 173 (4): 31-51.

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Table 1 The highest-ranking nouns of the frequency of appearancein Ricardo's Principles, Mill's Elements, and Martineau's Illustrations, No.25
Ricardo's Principles
Rank

Noun

Mill's Elements

Frequency

Noun

Martineau's Illustrations

Frequency

Noun

Frequency

1

price

1088 capital

446 labor

159

2

value

925 commodity

408 capital

148

3

commodity

750 labor

400 man

83

4

labor

684 value

341 time

80

5capital

637 quantity

314 society

77

6quantity

596 country

254 country

73

7

profit573 case

242 labourer

72

8

tax

568 money

213 principle

70

9

corn

552 wages

208 production

64

10

money

500 production

194 class60

11country

496 produce

187 commodity

58

12

rent

472 profit

184 proportion

56

13

produce

452 tax

179 capitalist

55

14

land

432 man

170 power

54

15

wages

410 land

168 money

51

16

production

284 price

159 case

50

17

proportion

277 demand

142 demand

44

18

rise

243 exchange

130 population

44

19

demand242 thing

127 exchange

43

20

labourer

216 portion

126 law42

21

effect212 labourer

122 value42

22

landlord

202 cloth

114 food

41

23

rate

201 corn

114 supply

41

24

goods

196 metal

114 state

40

25

market

191 rent

114 increase

38

26

gold

182 goods

112 wages

38

27

trade

176 proportion

106 means

37

28

time

164 cost

98 wealth

37

29

man

160 whole

97 number

36

30

farmer159 supply

93 people

36

Notes:The red indicates nouns included in the 10 highest-ranking in Ricardo's Principles.
The blue indicates nouns included in the 30 highest-ranking in Martineau's Illustrations only.

Figure 1-1

Figure 1-2

Figure 1-3

Figure 2-1

Figure 2-2

Figure 2-3