Abstract
Differences and similarities between countries, regions, and cultures lie at the core of international business, and they are often measured in the form of a distance index originally proposed by Kogut and Singh. Because research results using this index are ambivalent, critical observers have challenged the concept and proposed partial remedies in the form of a standardized Euclidean or Mahalanobis distance measure. This article suggests a different avenue, construes culture as a weight vector based on Hofstede’s cultural dimensions, and specifies a geometrical difference measurement using the angle of heterogeneity between two such vectors. Its performance is assessed using a mathematical simulation and an empirical example from the field of export marketing, which considers the effect of culture on bilateral export flows.
Keywords
Mathematical constructs conceptualizing and measuring cultural differences are widely used in international business, where they have been applied to most business administration disciplines—that is, management, marketing, finance, and accounting (Cuypers et al. 2018; Shenkar 2001). While these constructs have become an “international business research workhorse” (Beugelsdijk, Ambos, and Nell 2018, p. 1113), they are continuously and passionately being debated; some of these debates are still unresolved and complex.
After Hofstede (1980) proposed to measure culture and explain differences between cultures through four dimensions—namely, uncertainty avoidance (UAI), power distance (PDI), masculinity/femininity (MAS), and individualism/collectivism (IDV) 1 —Kogut and Singh (1988) had the groundbreaking idea that these four dimensions could be used to calculate an index of cultural distance. By treating these dimensions as bases in a Cartesian coordinate system, distances can be arithmetically measured using a derivative of the Euclidean formula. However, the application of the Kogut–Singh index in empirical research leads to mixed and contradictory results (e.g., Berry, Guillén, and Zhou 2010; Kim and Gray 2009; Kirkman, Lowe, and Gibson 2006; Yeganeh 2014). This may be, inter alia, the result of hitherto unresolved methodological problems (Shenkar 2001). For example, many researchers find the use of a composite measure appropriate (e.g., Beugelsdijk, Ambos, and Nell 2018; Cuypers et al. 2018), “whereas a growing number of others reject this outright as evidence of the ‘dark middle ages’ of cross-cultural research” (Tung and Verbeke 2010, p. 1270). The latter group argues that a generalized compound index gives equal weight to each component and does not allow researchers to distinguish the relevance of inputs for different research questions. Perhaps even more importantly, Hofstede’s cultural dimensions are correlated with each other. In other words, they form a nonorthogonal (oblique) feature space. In an oblique coordinate system, however, positions are generally not statistically independent of each other (Templeton 1959), and ignoring correlations between dimensions can thus lead to inaccuracies (Muir and Mallinson 1993). For that reason, various researchers have suggested incremental corrections to the Kogut–Singh index, including the use of a standardized Euclidean or Mahalanobis distance measure (Berry, Guillén, and Zhou 2010; Kandogan 2012; Konara and Mohr 2019). Further strands of literature take a more conceptual standpoint and debate the composition and measurement of cultural dimensions (e.g., McSweeney 2002; Messner 2016), discuss what factors should be included in a cross-national distance index (e.g., Berry, Guillén, and Zhou 2010; Ghemawat 2001), and examine whether cultural difference should be measured at the ecological or individual levels (e.g., Messner 2021a; Muthukrishna et al. 2020).
This article takes an entirely different avenue, completely abandons the arithmetic measurement of cultural distance, and replaces it with a geometrical measurement. To do so, culture is construed as a weight vector in a cultural feature space defined by Hofstede’s cultural dimensions or any other combination of cultural traits (following Desmet, Ortuño-Ortín, and Wacziarg [2017]). The angle between two such weight vectors is geometrically measured. Referred to as the angle of heterogeneity, angular distance, vector angle criterion, or cosine similarity in linear algebra, it is an indication of the cultural difference between two countries. Following established best practice in measurement development (Churchill 1979), the validity of the new geometrical cultural difference measure is empirically assessed in the context of export marketing. Cultural differences are hypothesized to be negatively related to bilateral export flows from India.
Accordingly, this article primarily contributes to the methodological international business literature. First, it sorts through existing measurements of cultural difference, reviewing their known methodological limitations and pinpointing hitherto unidentified problems. Second, and based on this appraisal, the article’s main objective is to develop a better operationalization of cultural difference through adopting a geometrical perspective. It is well-acknowledged that “high-quality research methods are a necessary building block for strong scholarship” (Eden and Nielsen 2020, p. 1609) and “necessary to move international marketing research beyond exploratory, qualitative comparisons” (Steenkamp 2001, p. 31). Third, and in a broader context, it naturally contributes to the use of cultural dimensions in country-level research (Beugelsdijk, Kostova, and Roth 2017; Brewer and Venaik 2012; Steenkamp 2001).
The article proceeds as follows. The subsequent section on the “Arithmetic Distance Measurement” reviews the construction of established arithmetic cultural difference measures. The pertinent literature is reviewed for known measurement issues and suggested improvements. Building on that, further and hitherto unknown conceptual issues are identified. Then, the “Geometrical Difference Measurement” section suggests a fundamentally different way of measuring cultural differences using the angle of heterogeneity between two cultural weight vectors. Drawing parallels from other disciplines, the applicability of this well-established geometrical measurement for cultural differences is discussed. To assess the measure’s validity, the “Effect of Cultural Differences on Exports” section provides an empirical illustration. Finally, in the “Discussion” section, the contribution of this methodological article to the field of international business and marketing is summarized.
Arithmetic Distance Measurement
Kogut–Singh Index
Because culture can be “defined as a vector of traits reflecting norms, values, and attitudes” (Desmet, Ortuño-Ortín, and Wacziarg 2017, p. 2479), a country’s culture can be characterized by its values on Hofstede’s k = 4 dimensions (Hofstede 1980). Accordingly, the cultural weight vector
Note that, for consistency purposes, variable names have been changed from Kogut and Singh’s original publication. Vi is the variance of the ith cultural dimension. However, Kogut and Singh do not provide a detailed explanation apart from stating that “this composite index was formed based on the deviation along each of the four cultural dimensions…of each country from [another country]. The deviations were corrected for differences in the variances of each dimension and then arithmetically averaged” (Kogut and Singh 1988, p. 422).
Euclidean Distance Measure
Despite prominent publications referring to the Kogut–Singh index as a Euclidean distance measure (e.g., Beugelsdijk, Ambos, and Nell 2018; Cuypers et al. 2018; Tihanyi, Griffith, and Russell 2005), Konara and Mohr (2019, p. 338) argue that “the use of the arithmetic average of the standardized and squared differences creates a fundamental difference” and suggest that a Euclidean cultural distance measure should be formulated as
or in a standardized form:
Comparing Equations 1 and 3, Konara and Mohr (2019, p. 338) note that “by failing to take the square root of the sum of the squared differences, the [Kogut–Singh index] creates a second-degree (quadratic) function of distance.” Figure 1, which is based on Konara and Mohr (2019, p. 344), shows the nonlinear relationship

Standardized Euclidean distance versus Kogut–Singh index.
Nonindependence of Cultural Dimensions
A substantial part of Hofstede’s work is dedicated to understanding interrelationships between cultural dimensions. For example, “many countries that score high on the power distance index…score low on the individualism index…, and vice versa. In other words, the two dimensions tend to be negatively correlated” (Hofstede and Hofstede 2005, p. 82). The GLOBE project (House et al. 2004), which is an alternative cultural framework outlining nine cultural dimensions and differentiating between societal and organizational values and practices, similarly highlights the interdependence of some dimensions. For example, the “societal collectivism scales are significantly correlated with other GLOBE dimensions. The more a society is characterized by institutional collectivism practices, the more it is characterized by uncertainty avoidance, future orientation, humane orientation, and performance orientation practices, and the less it is characterized by assertiveness and power distance practices” (Gelfand et al. 2004, p. 470).
This raises two issues. First, assuming the independence of cultural dimensions in a feature space is very naive. In addition, the variance-based correction factors in Equations 1 and 3 account for variance within a dimension but not for variance caused by correlations among dimensions (Carroll and Chang 1970). Yet ignoring correlations between coordinates in an oblique coordinate system can lead to inaccuracies in the estimation of standard deviations (Muir and Mallinson 1993). Because the Euclidean distance “neglects the existing correlations among cultural dimensions, [this] plausibly creates some inaccuracy in calculating the national cultural distance” (Yeganeh 2014, p. 442). Second, Hofstede’s cultural dimensions also suffer from different scales. Despite being depicted on a scale of 1 to 100, each dimension has a specific formula designed by Hofstede (e.g., Messner 2016). While Hofstede has “chosen [the] scales such that the distance between the lowest- and the highest-scoring country is about 100 points” (Hofstede and Usunier 2003, p. 141), this potentially affects similarity of the scales; that is, a score of 82 on PDI does not necessarily have the same meaning as a score of 82 on UAI. Positions on the dimensions are therefore not absolute, but relative (Hofstede 2011). If the dimensions were independent, the issue of different scales could potentially be solved by multiplying the scores with appropriate scaling factors (Shugart and Patten 1972). A similar problem persists in the GLOBE study. While all dimensions appear to be on a seven-point Likert scale, the underlying items have multiple different scale anchors (GLOBE 2006).
Because the correlations between Hofstede’s cultural dimensions lead to nonzero covariance, Berry, Guillén, and Zhou (2010), as well as Kandogan (2012) and Yeganeh (2014), suggest using the Mahalanobis distance instead (Mahalanobis, Bose, and Roy 1937):
In this formula, S is the covariance matrix for the four Hofstede dimensions, taking into account the nonorthogonality of the cultural feature space. The Euclidean distance is a special case of the Mahalanobis distance, with all covariances across dimensions being zero. A small correction brings the formula closer to the Kogut–Singh index in magnitude (Kandogan 2012):
The use of the generalized Mahalanobis distance measure as in Equation 4 is indeed recommended if the axes are of unequal scale and show a mix of high and low correlations (e.g., Berry, Guillén, and Zhou 2010; Brereton and Lloyd 2016; Shugart and Patten 1972). Despite this mathematically correct way out, the next section identifies new methodological problems, which so far have not yet been discussed in the pertinent literature.
Instability and Weight Effect of the Variance Correction
In some form or another, Equations 1, 3, 4, and 5 all contain the variance of cultural dimensions or between cultural dimensions as a correction factor. Variance calculations, however, depend on the number of countries included in the cultural dimensions. Scholars previously contemplated whether to calculate the distance based on the variance of the full sample for which scores are available or for the subset of countries they include in their study. The prevailing recommendation is to use the variance of the full sample (Beugelsdijk, Ambos, and Nell 2018).
However, a variance correction assumes a normal probability distribution of the scores on each cultural dimension. As a Shapiro–Wilk test shows, only the country scores for PDI and MAS are normally distributed (W(78) = .984, p = .416; W(78) = .981, p = .307, respectively). IDV and UAI do not follow a normal distribution (W(78) = .942, p = .001; W(78) = .952, p = .005 respectively); histograms show that the deviation is not trivial. A Kolmogorov–Smirnov test with the Lilliefors significance correction arrives at an equivalent conclusion (PDI: W(78) = .071, p = .200; IDV: W(78) = .109, p = .023; MAS: W(78) = .081, p = .200; UAI: W(78) = .116, p = .011). From a strict mathematical point of view, a variance correction of cultural scores is thus not appropriate, regardless of whether the Kogut–Singh (Equation 1), the standardized Euclidean distance (Equation 3), or the Mahalanobis distance formula (Equations 4 and 5) is used. In addition, the four original Hofstede dimensions are currently available for no more than 75 countries and 3 regions (Africa East, Africa West, and Arab countries). The GLOBE study is available for only 62 societies, out of the world’s 195 recognized countries. Should additional data be collected from other countries and added to the full Hofstede or GLOBE sample, all variances would have to be recalculated. As a result, the cultural distance between two countries A and B changes every time a new country is added to the database—even though the countries’ positions

Kogut–Singh index with variance correction for 39 versus 78 countries.
With the variance correction factor, the Kogut–Singh formula (Equation 1) attaches a different weight to each of the squared differences. The variance correction factors are 508.129 for UAI, 441.556 for PDI, 346.798 for MAS, and 574.634 for IDV, as calculated for all 78 countries. Thus, Equation 1 effectively becomes
When calculated for the first 39 entries in the Hofstede tables, the variance correction factors are 458.958 for UAI, 422.362 for PDI, 238.780 for MAS, and 656.580 for IDV, and Equation 6 turns into
Lin’s concordance correlation between these two sets of correction factors is .821 with limits [.506, .942], which is considered a poor to moderate agreement. The question arises whether these weights really compensate for different variances, or whether they arbitrarily impose weights on the dimensions. Several reasons speak for the latter. First, and as mentioned previously, Kogut and Singh do not give an explanation for introducing the variance correction factor and even state that this “scaling method imposes weights based on index variance” (Kogut and Singh 1988, p. 422; italics added). Second, these weights give the most importance to MAS and the least importance to IDV. The latter arguably has the most influence on aspects of customer service (Donthu and Yoo 1998; Obal and Kunz 2016; Soares, Farhangmehr, and Shoham 2007). Reducing the number of countries in Equation 7 further amplifies this difference. The issues caused by dynamic variance correction based on measured variance of variables are well-acknowledged in chemical engineering (e.g., Attarwala 2011). In magnetic resonance imagining, the challenge posed by numerical stability of fixed-point noise variance correction formula for separating signal intensity from noise is also well recognized (e.g., Koay and Basser 2006). Scholars in the statistical sciences are also aware of the issue and attempt to advance methods for capturing population variance in successive sampling (e.g., Singh et al. 2011). Third, UAI plays an important role in marketing research (see references in Messner [2016]), but the variance correction factor diminishes the relative influence of UAI as compared with MAS and PDI. More systematically, Yeganeh (2014) uses the Human Development Index (HDI; Roser 2020) to understand the varying importance of cultural dimensions, based on the premise that socioeconomic and cultural factors are strongly correlated (see references in Yeganeh [2014]). Regressing HDI on the cultural dimensions indicates a collective significant effect (R2 = .488, F(4, 65) = 15.531, p < .001). But only PDI (−1.403, p = .021) and IDV (2.322, p = .021) are significant predictors in the model, and UAI (.526, p = .225) and MAS (−.284, p = .581) are not significant. 4 So, the variance correction factors in the Kogut–Singh formula give the least importance to the most important predictor, IDV, and the most importance to MAS, a nonsignificant predictor. And because the IDV scores are not normally distributed across countries (as discussed previously), an IDV variance-correction factor should not have been calculated in the first place. In view of that, it is not surprising that the application of the Kogut–Singh index in empirical research leads to mixed results (for an overview, see Yeganeh [2014]).
Thus, it is now time to move to the core of the research, replace the Euclidean arithmetical distance calculation with its myriad correction attempts, and propose a mathematically correct method.
Geometrical Difference Measurement
Angle of Heterogeneity
Linear algebra distinguishes between arithmetically calculating distances in a coordinate system and geometrically measuring the length and direction of vectors in a feature space. Mathematically, a weight vector (or feature vector, observation vector) is an n-dimensional vector of numerical features that represent some object. The vector space associated with these vectors is called the feature space (e.g., Nagamochi 2009). A cultural feature space, for example, can be defined by Hofstede’s n = 4 dimensions. And a country’s cultural summary on these four dimensions can consequently be understood as a four-dimensional weight vector (Desmet, Ortuño-Ortín, and Wacziarg 2017). Geometrically, the length and direction of a vector are its true identity, not its coordinates, because the length and direction are unaffected by changes in the feature space. The angle
The Mathematical Appendix explains how this formula is derived from the dot product between two vectors, and Figure 3 illustrates it graphically for two countries (Argentina

Hofstede-based weight vectors for Argentina (ARG) and Austria (AUT).
Following the property of the cosine function, the definition in Equation 8 provides information about the way two vectors are aligned with each other. The angle
Application Across Disciplines
In several fields and disciplines, the angle of heterogeneity is used to describe the difference between two weight vectors (e.g., Grzegorczyk, Kurdziel, and Wójcik 2016; Salton and McGill, Michael 1983; Sim et al. 2019). It is “the most widely reported measure of vector similarity” (Ye 2011, p. 91) and applied where common characteristics need to be measured (Xia, Zhang, and Li 2015). For example, in computer graphics, the RGB color model knows red, green, and blue as three primaries, which can produce the color gamut (Salomon 2011). Because color is defined in the RGB color space as relative values in the trichromatic channel and not as triplet values of absolute intensity, a difference measure between two colors must respond to chromaticity (relative intensity) and not luminance (absolute intensity) difference (Plataniotis, Androutsos, and Venetsanopoulos 1998; Trahanias and Venetsanopoulos 1993). The angle of heterogeneity is also used to compare spectral images with a reference image (Deborah, George, and Hardeberg 2014; Kruse and Lefkoff 1994). In image processing, a difficult problem is to accommodate for superficial differences arising from the vagaries of illumination (Viola and Wells 1997). Because the angle of heterogeneity uses only the vector direction and not the vector length, it ensures low sensitiveness to illumination conditions (Lasaponara and Masini 2012). In database applications, it is used for approximate string matching predicates on text attributes (Li and Han 2013; Tata and Patel 2007). In market research, a distance metric based on the angle of heterogeneity can be used to assess the repeatability and reproducibility of consumer preferences (Vanacore et al. 2019). Nautical astronomy, however, uses
Application for Measuring Cultural Differences
Similar to color in the RGB model, and as outlined previously, a country’s culture is a combination of positions on the cultural dimensions, referred to as the vector of traits (Desmet, Ortuño-Ortín, and Wacziarg 2017). The angle of heterogeneity
Hofstede-Based Cultural Difference Measures: Angle of Heterogeneity θ (Below Diagonal) and Kogut–Singh Index (Above Diagonal).
While
The country weight vectors
Evaluation of Construct Validity
To contrast the overall quality of the geometrical measurement with the Kogut–Singh index, multidimensional scaling (MDS) is deployed on both difference measures. MDS is a technique used to determine coordinates for a set of objects in a n-dimensional space, strictly using matrices of pairwise differences between these objects (Giguère 2006). The geometrical measurement has lower stress levels and higher levels of variance explained than the arithmetical measurement (
Figure 4 compares the angle of heterogeneity with the Kogut–Singh index for all 6,006 country pairs. Lin’s concordance correlation is poor at .117 with limits [.113, .121]; the Bland–Altman test shows a mean difference of .862 (SE = .008, SD = .683),
5
and the second-order polynomial trendline through the origin is

Angle of heterogeneity θ versus Kogut–Singh index.

Angle of heterogeneity θ versus standardized Euclidean distance.
These effects of convergent and discriminant validity (Churchill 1979) can be pointed out with a mathematical simulation. Let two countries A and B be characterized by vectors

Simulating the performance of difference measures.
These effects owe to the fact that the
In addition, and related to this discussion, at least a two-dimensional feature space is required for calculating the angle of heterogeneity. Vectors do not exist in a one-dimensional feature space, and so Equation 8 returns 0 whenever k = 1.
Effect of Cultural Differences on Exports
The construct validity of the angle of heterogeneity as a new geometrical cultural difference measure is next illustrated with an empirical example and an exemplary research hypothesis. This follows suggestions for best practices in measurement development (Churchill 1979) and prior literature on developing and comparing cultural difference measures (e.g., Berry, Guillén, and Zhou 2010; Kim and Gray 2009) as well as other measurement tools (e.g., concordance correlation [Lin 1989], necessary condition analysis [Messner 2021b], outlier detection [Mullen, Milne, and Doney 1995], cosine similarity [Tata and Patel 2007]).
Research Hypothesis
Prior studies on export marketing have consistently found that cultural differences are negatively related to bilateral export flows (e.g., Cyrus 2012; Shoham and Albaum 1995; Slangen, Beugelsdijk, and Hennart 2011; Sousa and Tan 2015; Tadesse and White 2010). Export flows from India are a good case study because typical confounding factors in export marketing, such as the existence of land borders, do not play a major role for India. Most of the country’s exports go through sea- and airports, rather than land border crossings. There is no trade between India and China via the land route, trade between India and Pakistan through the land route is very limited, and trade volumes with Myanmar and Bhutan are also relatively low. While trade with Bangladesh is mainly carried out by road, it is also supplemented with coastal shipping. Note that, until 2015, Indian vehicles were not even allowed to enter Bangladesh, Bhutan, and Nepal (Sinate, Fanai, and Joy 2018). More formally, the following hypothesis is tested:
Research Model and Data
The dependent variable in the research model is the average export volume to India’s 194 partner economies from 2014 to 2018 (WTO 2019). The main independent variable is cultural difference, separately operationalized with the angle of heterogeneity (Model A), the Kogut–Singh index (Model B), Euclidean distance (Model C), and Mahalanobis distance (Model D). The Hofstede dimensions are directly available for 68 of the 194 partner countries; no substitutions for neighboring countries are made, and the general Hofstede scores for Africa West, Africa East, and Arab countries are not used. Three additional variables are introduced into the model: First, gross domestic product (GDP) measures the size of the partner economy. Second, GDP per capita in purchasing power parity (PPP) approximates the national income. Both are calculated as a ten-year average from 2010 to 2019 (World Bank 2020a, b), and a positive association with export volume from India is expected. Third, the physical distance to a partner economy is calculated as the air distance between New Delhi and the partner economy’s capital city (https://www.timeanddate.com/worldclock/distance.html); a negative association with export volume is expected (e.g., Frankel, Stein, and Wei 1997; Ghemawat 2001; Sheng and Mullen 2011).
Results
The four models using different cultural difference measures are estimated separately with a linear regression in SPSS 27. Cook’s D, an influence statistic measuring the impact of an observation on all regression coefficients (Everitt and Skrondal 2010), identifies the United States and China as outliers. Depending on the model, Cook’s D for the United States is between 9.882 and 10.848. For China, the angle of heterogeneity in Model A produces the lowest (D = 1.266) and Model C the highest (D = 1.542) statistic. All other countries are inconspicuous. With a share of 16.02% and 5.08%, respectively, the United States and China are India’s largest and third-largest trading partners, which justifies them being considered outliers. Thus, the models are estimated again without the United States and China; the results are shown in Table 2.
Empirical Illustration: Export Volume From India.
Cultural differences negatively and significantly influence the export volume in all four models, which confirms H1. In addition, the partner economy’s GDP exerts a positive and significant effect. The effect of GDP per capital PPP, however, is not significant. The physical distance of the partner economy from India is negatively associated with the export volume, but the effect is significant for only Models B (−142.549, p = .026) and D (−131.176, p = .047); it is not significant for Models A (−129.688, p = .053) and C (−116.025, p = .073).
As a robustness test, the necessary impact of a potentially unobserved confound for invalidating the inference that cultural difference is associated with India’s export volume is examined (following Frank [2000], Frank et al. [2013], and Rosenberg, Xu, and Frank [2018]). In Model A, such a confounding variable would have to be correlated with the angle of heterogeneity and the export volume at .423. In addition, the robustness with respect to external validity is examined by determining that 37.775% (or 25 countries) would have to be replaced with unobserved cases for which the null hypothesis is true to invalidate the inference. This thought experiment helps defend a potential concern that the 66 countries for which the Hofstede dimensions are available may not be representative for all 194 partner economies.
Model Comparison
The negative influence of cultural differences on export volume is confirmed in all four models with high statistical significance, albeit with some notable differences. At first glance, the angle of heterogeneity in Model A has a lesser statistical significance (−7.393, p = .002) than the Kogut–Singh index (Model B; −1.344, p < .001), Euclidean distance (Model C; −.086, p < .001), and Mahalanobis distance (Model D; −1.318, p = .001). Generally, multicollinearity is not an issue in any of the models; the variable inflation factor never exceeds 1.258. The collinearity diagnostics tables, however, show lower condition indices and associated variance proportions for Models A and D. However, there is a slight multicollinearity effect in Models B and C, which seems to marginally increase the significance of coefficients in these models.
Next, a comparison of the absolute values of the standardized regression coefficients provides a rough indication of the importance of the variables in the models (Siegel 2017). Potential concerns about comparing coefficients directly between models can be alleviated by very similar overall model fits; the R2 values fall within a range from .427 (Model A) to .467 (Model C). In Model A, the importance of the angle of heterogeneity is 45.799%, calculated as .338/(.402 + .193 + .207 + .338). However, in Models B, C, and D, the importance of the cultural distance measure is only 31.118%, 32.728%, and 30.001%, respectively. Across the models, the angle of heterogeneity attracts the highest importance.
In the four models, the choice of cultural difference measure also influences the statistical significance of the regression coefficient for geographical distance. A stream of literature finds that developing countries often face higher costs to export, and that within-country infrastructure to transport increases border costs (Van Leemput 2016; e.g., Limão and Venables 2001). For example, each day in transit adds costs up to an ad valorem tariff of 2.3% (Hummels and Schaur 2013). India is notorious for its dismal transport infrastructure and long customs clearing time at its ports (Mackie and Greer 2012). This arguably reduces the influence of intercountry transportation costs to overall logistics costs. In addition, shipping rates are influenced by not only geographical distance but also competition, overall trade volume, direction, and season. 8 Thus, models with a negative but statistically nonsignificant coefficient might be the more accurate ones for developing economies, which further supports the choice of the angle of heterogeneity as a cultural difference measure.
Taken together, this illustrative empirical analysis reveals that the angle of heterogeneity is indeed a different construct from the Kogut–Singh index, Euclidean distance, and Mahalanobis distance (discriminant validity; Churchill 1979) and might be better suited for examining international business research questions.
Discussion
This research does not propose a new approach to conceptualizing or examining the influence of cross-national cultural difference. Instead, it reviews and highlights why the Kogut–Singh index, the (standardized) Euclidean distance measure, and the Mahalanobis distance are unsuitable mathematical tools when applied to cultural dimensions. The use of deficient measures—that is, measures that do not fully capture the construct or are not sufficiently reliable—has been identified as the most frequent challenge in international business research (Aguinis, Ramani, and Cascio 2020; Eden and Nielsen 2020). Because the concept of cultural difference continues to play a central role in international business research and managerial practice, the use of a mathematically correct measure is paramount (Konara and Mohr 2019).
In this vein, this article first identifies the methodological shortcomings of arithmetic distance measurement with respect to cultural dimensions. First, cultural dimensions are undoubtedly interrelated and therefore a nonorthogonal feature space. Second, due to the design of Hofstede’s dimensions, a country’s position on a cultural dimension is a relative position, but not an absolute position. Third, country scores on cultural dimensions are not normally distributed, which makes a variance correction unsuitable from a mathematical point of view. Fourth, country scores are only available for less than half of the world’s countries; for that reason, variance and covariance correction factors are instable and should not be used. In addition, variance correction factors introduce counterintuitive weights contradicting much of extant international business research. The adverse influence of the weight effects is demonstrated in this article.
As a contribution to the international business methodology literature, the article then offers a geometrical measurement of cultural differences based on the angle of heterogeneity between two cultural weight vectors. This metric measures common characteristics (Xia, Zhang, and Li 2015) and thus expresses how related (or different) two countries are. It does not necessitate independence of the cultural dimensions, does not call for the dimensions to have equivalent measurement scales, and produces identical results independent of the number of countries the dimensions are based on. The MDS technique shows that there is less conflict present in the geometrical difference measurement than in the Kogut–Singh index. An empirical example using export volumes as a dependent variable illustrates that the angle of heterogeneity has noteworthy and appropriate effects in a linear regression model as compared with other arithmetical measures. The angle of heterogeneity reduces multicollinearity between the independent variables and emphasizes the relative importance of cultural differences as compared with other variables. Future research should certainly investigate these effects in other business administration disciplines.
Setting aside these advantages, two limitations of the angle of heterogeneity should be noted. First, geometrical measurement does not detect a difference between two countries if their weight vectors are multiples of each other. While such a constellation is purely theoretical, this article shows that this feature actually reduces cultural differences in survey response styles. Second, because geometric measurement works on vectors defined in a multidimensional feature space, at least two dimensions are required. It is therefore not possible to calculate separate angles of heterogeneity for UAI, PDI, MAS, or IDV; the angle of heterogeneity is a composite measure (Schnack and Kahn 2016) requiring at least two dimensions. Commentators disagree on how many dimensions should be aggregated into a measure of cultural difference. One view recommends calculating the measure separately for multiple dimensions, as called for by theoretical and domain considerations (Shenkar 2001). The angle of heterogeneity does not support this view. While a Euclidean distance measure could theoretically be used, the extant international business literature has not yet evaluated different forms of single-dimension difference measures. This opens up promising avenues for future methodological research. In contrast, other commentators argue that an overall measure integrating as many dimensions as possible, even from competing frameworks, picks up more variation in cultural differences (Beugelsdijk, Ambos, and Nell 2018; Beugelsdijk, Kostova, and Roth 2017; Steenkamp 2001). Geometric measurement is much better equipped to support this view than arithmetic formulas because it does not require the dimensions to have comparable scales and scale anchors. Using dimensions from several frameworks with the angle of heterogeneity would further reduce the already unlikely occurrence of linear dependence between two countries. Further research could attempt to portray these effects.
Although measuring the angle of heterogeneity between two vectors is well established in linear algebra and regularly used in applied fields such as computer image processing, it has not yet been exploited by international business researchers. Equation 8 is easy to compute with a spreadsheet or in any statistical program. It is therefore my hope that the proposed geometrical measurement of cultural difference using the angle of heterogeneity between two cultural weight vectors will help resolve some of the inconsistencies reported in the international business and marketing literature concerning the effects of arithmetic distance indices, such as the Kogut–Singh index, the (standardized) Euclidean distance index, and the Mahalanobis distance.
Footnotes
Mathematical Appendix
The Mathematical Appendix explains how the formula for the angle of heterogeneity (Equation 8) is derived from the dot product between two vectors.
The arithmetic calculation is the dot product (or inner product or scalar product) between two weight vectors. It is a “dimension-reducing operation” (Farouki 2007, p. 82) resulting in a scalar value:
When the dot product is zero, the two vectors have an angle of
The norm (or length or magnitude) of a vector is defined as
Let M be the (hyper)plane spanned by two vectors
Equation MA.3 is generally used to define the cosine of the angle between two vectors:
or
Equation MA.4 is commonly referred to as cosine similarity (e.g., Ye 2011). The effect of the denominator in Equation MA.5 is to length-normalize the vectors
As the angle approaches
List of Abbreviations and Mathematical Symbols
Associate Editor
Babu John Mariadoss
Acknowledgments
The author is very grateful for insights, suggestions, and constructive guidance offered by the JIM review team, which led to substantial changes and improvements in this article. Any errors remaining are the responsibility of the author.
Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author’s research work is partly funded through the Center for International Business Education and Research (CIBER) at the University of South Carolina.
