In his seminal work, Pierre Bourdieu (1973, 1986) distinguished three fundamental forms of capital that, in his view, allow for a more complete and nuanced understanding of social reproduction and the societal distribution of power. According to his conceptualization, economic capital refers to economic resources (e.g., income, property). Social capital refers to resources available through social ties and membership in social networks. Cultural capital comprises “instruments for the appropriation of symbolic wealth worthy of being sought and possessed” (Bourdieu, 1973, p. 175). Regarding the conversion of the three forms of capital, Bourdieu (1986) posited that social and cultural capital can be construed from economic capital to a certain degree but only with much effort. This implies on the one hand that economic capital is fundamental to the other capital forms and on the other hand that social and cultural capital cannot be reduced to economic resources (Bourdieu, 1986).

In his later work, Bourdieu distinguished between three more specific forms of cultural capital: incorporated, institutionalized, and objectified cultural capital (Bourdieu, 1979). Incorporated cultural capital is understood as an individual’s inherent and lasting disposition influenced by processes of formal education and individual socialization. Institutionalized cultural capital grants institutional or public recognition mostly represented by academic titles. It is, under the right circumstances, convertible into economic capital (Koller, 2009). Finally, objectified cultural capital comprises tangible cultural goods such as books or works of art that can, in contrast to incorporated cultural capital, be physically transferred. It is the latter form of cultural capital that the widespread “number of books in the household” items capture.

Initially, Bourdieu introduced the concept of cultural capital in an attempt to explain how social status is reproduced through a society’s educational system (Bourdieu, 1973, 1984, 1986; Bourdieu & Passeron, 1990; Lareau & Weininger, 2005). He accorded a pivotal role to the intergenerational transmission of cultural capital, by which children are endowed with parental cultural capital during the process of socialization. Bourdieu and Passeron (1990) argued that children profit the most from parental cultural capital when their parents are of a high social status, that is, if parents have accumulated greater amounts of cultural capital. Those children are better prepared for higher levels of education and receive greater rewards during their educational career (e.g., in form of better school grades). This recreation of social privilege is known as the Cultural Reproduction Theory. In contrast to Bourdieu’s ideas, DiMaggio (1982) found that male students benefit the most from their parental cultural capital if their fathers had a low to medium socioeconomic status. He concluded that children whose parents are of a lower socioeconomic standing are better able to use their parental cultural resources as an additional asset to their measured ability on their way to higher education. He names this the Cultural Mobility Theory (DiMaggio, 1982).

Today’s predominant interpretation and operationalization of cultural capital can be traced back to the work of DiMaggio (for reviews, see Kingston, 2001; Lareau & Weininger, 2005). He filled in Bourdieu’s sometimes unclear and inconsistent explanations of how incorporated cultural capital is associated with individual educational outcomes (Lamont & Lareau, 1988; Kingston, 2001; Sullivan, 2001; Lareau & Weininger, 2005) by arguing that “schools reward students on the basis of their cultural capital ["]. Teachers ["] communicate more easily with students who participate in elite status cultures, give them more attention and special assistance, and perceive them as more intelligent or gifted than students who lack cultural capital” (DiMaggio, 1982, p. 190). Thus, DiMaggio specified a mechanism through which cultural capital can contribute to individual educational outcomes. Consequently, DiMaggio’s cultural capital follows a Weberian notion of “elite status groups”, according to which specific traits, tastes, and styles within a social group generate “a common sense of honor based upon and reinforced by shared conventions” (DiMaggio, 1982, p. 189). He operationalized cultural capital as participation in cultural activities that represent a high social status such as visiting the museum and theater or enjoying classical music (cf. Kingston, 2001; Lamont & Lareau, 1988; Lareau & Weininger, 2005).

Despite the elaborate theoretical underpinnings of the cultural capital concept, little effort has been devoted to the question as to how cultural capital should best be measured (Kingston, 2001; Dumais, 2006). Although Bourdieu suggested a range of indicators of cultural capital that he used in his empirical work (Bourdieu, 1973), there are no established “gold standard” indicators of cultural capital (Kingston, 2001; Dumais, 2006). Research has used widely varying measures, often chosen ad hoc, and the validity of even the most widely used indicators is largely unclear.

Teachman (1987) was one of the first to use measures of objective parental cultural resources that foster academic success and which are not bound to family demographics (see also Leibowitz, 1977). In his study, he focused on educational resources measured through four items asking if, in the respondents’ home, there were a place to study, a daily newspaper, a dictionary, or an encyclopedia and if there were reference books (Teachman, 1987, p. 550).

Subsequently, an item asking respondents how many books there were in their family's home when they were 16 years old has emerged as one of the most widely used operationalizations of objectified family cultural capital. This single-item measure has been used, for example, in large-scale international comparisons conducted by the Organization for Economic Co-operation and Development (OECD; e.g., OECD, 2011). Apart from its face validity, however, the quality of this measurement approach has rarely been systematically scrutinized.

The aim of our present analyses is to fill this gap. Specifically, we analyze the measurement properties (e.g., objectivity, reliability, and especially validity) of the aforementioned item measuring past cultural capital through the number of books in the respondent family's home at age 16. Moreover, we analyze a slightly rephrased variant of this item that measures present cultural capital through the number of books in the respondent's current household. For his purpose, we draw on a large sample of German adults.

Item generation and selection

The items are part of the Programme for the International Assessment of Adult Competencies (PIAAC) and the Programme for the International Assessment of Adult Competencies - Longitudinal’s (PIAAC-L) Background Questionnaire. They are presented in the context of other sociodemographic questions such as educational attainment or country of birth. No specific instructions were given for the items. The respondent is provided with a show card that depicts the response categories before the interviewer reads the survey question face-to-face (OECD, 2010).

PIAAC 2012 Germany only collects respondents’ information on the number of books in the home at age 16 (Table 1, Item 1). Respondents who are 16 years of age at the time of the interview are asked about the present number of books in their home. Within PIAAC, this item was translated and administered in more than 33 countries (see PIAAC-Home for a survey overview).

Samples

The main data source for the present analyses is the second (2015) wave of the Survey of Adult Skills’ (PIAAC) follow-up study PIAAC-L Germany (version 2.0.0), because only in PIAAC-L participants responded to both items of interest; past and present number of books at home. Additionally, PIAAC-L enhances and elevates the cross-sectional approach of PIAAC 2012 Germany into a longitudinal design by re-contacting and re-interviewing PIAAC 2012 participants. Therefore, PIAAC-L does not draw a new probability-based sample but is a subsample of all PIAAC 2012 respondents[2] and their household members who were willing to participate in the follow-up (further information on the sample design and sample selection is available at  PIAAC-Home, PIAAC-Longitudinal, and PIAAC-Documentation).

Combining PIAAC 2012 and PIAAC-L 2015 allows us to estimate the test-retest reliability for the item number of books at age 16, which was measured in both surveys. The subsample for these analyses consists of participants who participated in both surveys. Test-retest reliability cannot be tested for the present number of books at home because this item was only assessed once, in PIAAC-L 2015.

[2] Each participating country in PIAAC 2012 administered a probability-based random sample representative of the respected working-age adult population.

Objectivity

In PIAAC, three steps were taken to ensure measurement objectivity. First, only interviewers with excellent track records and previous experience with PIAAC field tests are considered as PIAAC interviewers and received extensive training. Second, as described above, respondents are provided with a show card of response categories before the interviewer reads out the question. Third, the wording of the survey items gives respondents an estimate on how many books fit on 1 meter of shelving. These applications guide objective responding and reduce interviewer effects (Zabal et al. 2013).

Reliability

The test-retest reliability (i.e., temporal consistency), measured by Spearman’s rho and Kendall’s tau_b of the item measuring past objectified cultural capital (number of books at age 16) is ρ = .74 and τ_b = .65, respectively. Given the period of 3 years that elapsed between the measures, this indicates a satisfactory test-retest reliability of the item. This finding further applies across different age groups, as shown in Table 2. In all age groups, the 3-year test-retest reliability exceeds ρ = .70 and τ_b = .60.

Table 2

Temporal Consistency of “The number of books in the home when respondent was 16 years old”

Note. Spearman’s rho and Kendall’s tau_b by age groups. Item scale from 1 ("10 books or less") to 6 ("More than 500 books"). Estimates based on respondents that responded to the item in PIAAC 2012 and PIAAC-L 2015. Complete case analysis

Validity

To judge the construct validity of the two items under consideration, we inspect their correlations with a range of other measures based on the sample of German PIAAC-L 2015.

Our focus in assessing validity is on three questions: First, whether the items measuring past and present number of books at home are associated with one another. Second, whether the items of past and present number of books at home are associated with other often-used indicators of incorporated cultural capital and present books-related activities (convergent validity). Third, whether the items of past and present number of books at home measure something different than socioeconomic status or acquired skills (divergent validity).

(1) Associations between past and present objectified cultural capital. Considering the correlation between past and present objectified cultural capital, we found a moderate correlation (Spearman’s rho) of ρ = .52 between the number of books at age 16 and the present number of books at home in the current household among the PIAAC-L 2015 respondents.

This correlation suggests that there is indeed a substantial intergenerational transmission of cultural capital: Respondents with a higher number of books in their family of origin’s household possess a higher number of books in their own household later in life. It must be noted, however, that memory bias might inflate this correlation to an unknown extent.

(2) Convergent validity. Correlations with cultural and literary activities. To assess convergent validity, we examine the correlations of past and present number of books with two other often-used measures of cultural capital, namely cultural activities (visiting cultural events and visiting cultural places). Additionally, we look at the association of past and present books at home with present literary activities (e.g., reading, visiting the library). These items can be seen as proxies of incorporated cultural capital. All four activity items are measured with a 5-point ordinal scale that asks respondents about the frequency of each activity: 1 = “Daily”, 2 = “At least once a week”, 3 = “At least once a month”, 4 = “Less frequently”, 5 = “Never.” We recoded these activity items so that higher values indicate more frequent behavior.

As to be expected, both number-of-books items correlate positively (.21 ≤ ρ ≤ .36) with cultural activities, whereby the number of books in the present household – plausibly – exhibits stronger relations to these measures of cultural capital than the number of books at age 16 does. They also show moderate associations with literary activities.

Importantly, the only small to medium-sized correlations with cultural and literary activities support the idea that cultural capital is not a homogeneous construct, as one might expect from Bourdieu’s distinction between objectified, incorporated, and institutionalized cultural capital. This implies that different measures of cultural capital capture partly distinct aspects of the same overarching construct (e.g., Jæger, 2011). Specifically, these correlations reflect the demarcation of incorporated cultural capital as assessed by the cultural events/places measures and objectified cultural capital assessed by the number-of-books items.

(3) Divergent validity. To test the two items’ divergent validity, we examine their correlations with (1) years of formal education and occupational prestige as measures of socioeconomic status and (2) respondents’ literacy and numeracy skills as indicators of acquired skills that facilitate academic success. Literacy and numeracy skills were measured with the extensive tests from the PIAAC framework. In that regard, Table 3 shows moderate correlations (Spearman’s rho: .30 ≤ ρ ≤ .40) of the past and present number of books with the indicators of socioeconomic status.

The two number-of-books items also correlated as expected (.29 ≤ ρ ≤ .43) with literacy and numeracy skills.

Following DiMaggio’s (1982) general understanding of cultural capital as being distinct from skills and abilities (see also Lareau & Weininger, 2005), one might expect only weak correlations of the past and present number of books at home with literacy and numeracy. Our findings show that objectified cultural capital as measured by the number of books has at least moderate correlations with both sociodemographic status and skills (Table 3). Still, these correlations are weak enough to support the divergent validity of the two number-of-books items. The two number-of-books items also correlated as expected (.29 ≤ ρ ≤ .43) with literacy and numeracy skills.

Table 3

Convergent and Divergent Validity of the Past and Present Cultural Capital Measures in PIAAC-L 2015

Note. N = 3263. Observations vary. Cell values are Spearman’s rho. Kendall’s tau_b in parentheses. Correlations of pairwise present observations.

Descriptive statistics (scaling)

Tables 4 and 5 present descriptive statistics for the two “number of books” items for the total German PIAAC-L 2015 sample and separately by age group. Although the distributions of the two items for the total sample are similar, the separation by age groups highlights that older cohorts of respondents report having had fewer books at home at age 16 compared to younger cohorts. Additionally, older cohorts tend to possess more books at home in their present households than younger cohorts do. This may reflect the changing value of books as a form of objectified cultural capital.

Table 4

The Number of Books in the Home when Respondent was 16 Years old

Note. Valid frequencies by age groups for PIAAC-L Germany 2015 (column percentages in parentheses). Absolute total missing values: 24

Table 5

The Present Number of Books in the Home

Note. Valid frequencies by age groups for PIAAC-L Germany 2015 (column percentages in parentheses). Absolute total missing values: 3

Further quality criteria

Due to its short completion time (< 1 min), the instrument can be seen as economic.

Further literature

The scale was first published in the journal Measurement Instruments for the Social Sciences.