5. Meta Analysis
5.2 Results
5.2.8 Purchase Intention and Willingness to Buy Domestic
For analyzing whether consumer ethnocentrism is related to consumers preferring to buy domestic products, 25 studies were included. The overall weighted average effect size is very positive, with the random effects models producing an r of 0.3319. Both tests conducted for assessing heterogeneity show high heterogeneity, with the Q value being significant at the p<0.0001 level.
Table 5.36 Weighted average effect sizes of PIWTB domestic
COR 95%-CI z p-value
Fixed effect model 0.3178 [0.2981; 0.3372] 29.67 < 0.0001 Random effects model 0.3391 [0.2675; 0.4069] 8.78 < 0.0001
Table 5.37 Analyzing heterogeneity of PIWTB domestic Quantifying heterogeneity
I² 91.9% [89.3%; 93.9%]
Test of heterogeneity
Q d.f. p-value
296.92 24 < 0.0001
Graphical depiction of the findings in the forest plot reveals that all effect sizes are positive, although they do vary across studies, with the lowest effect size found by He and Wang (2015) with 0.08 and the highest effect size found by Wang and Cheng (2004) with 0.62.
Figure 5.22 Forest plot of PIWTB domestic
Distribution of the z transformed correlations in the funnel plots further depicts the scattered correlations and shows that there are quite a few studies with very low standard errors.
Study
Fixed effect model Random effects model
Heterogeneity: I2 = 92%, τ2 = 0.0357, p < 0.01 Shimp & Sharma 1987
Shimp & Sharma 1987 Shimp & Sharma 1987 Shimp & Sharma 1987 Parts & Vida 2013 Parts & Vida 2013 Huang et al. 2008 Nguyen et al. 2008 Wang & Cheng 2004 Zeugner−Roth et al. 2015 Zeugner−Roth et al. 2015 He & Wang 2015 Suh & Kwon 2002 Suh & Kwon 2002 Huang et al. 2010 Nijssen & Douglas 2004 Nijssen & Douglas 2004 Rose et al. 2009 Rose et al. 2009 Rose et al. 2009 Rose et al. 2009 Douglas & Nijssen 2003 Selli & Kurniawan 2014 Parker et al. 2011 Mostafa 2010
Figure 5.23 Funnel plot of PIWTB domestic
The Trim-and-Fill Method reveals that missing studies lie on the lower spectrum of the observed correlations. These studies could be left unpublished, as low results are less likely to be published. If missing values were retrieved, the overall weighted average effect size would therefore be lower.
Figure 5.24 Filled funnel plot of PIWTB domestic
Since the PIWTB domestic construct consists of the three measures purchase intention domestic, willingness to buy domestic, and reluctance to buy foreign, moderator analysis on the type of construct was performed next. Overall, reluctance to buy foreign produced higher effect sizes than the other two constructs, which were relatively the same. This can be explained due to the definition of the construct, which may evoke stronger sentiments than the other two constructs simply asking for preference. Nevertheless, between group differences in
0.1 0.2 0.3 0.4 0.5 0.6 0.7
0.100.080.060.040.020.00
Fisher's z transformed correlation
Standard Error
−0.2 0.0 0.2 0.4 0.6
0.100.080.060.040.020.00
Fisher's z transformed correlation
Standard Error
the random effects model were not significant, and the constructs will therefore continue to be analyzed as a whole in the following.
Table 5.38 Analysis of PIWTB domestic for moderator construct Test for subgroups (random effects model)
k COR 95%-CI Q I²
Construct = 0 6 0.3155 [0.1884; 0.4322] 43.55 88.5%
Construct = 1 6 0.3024 [0.0995; 0.4812] 199.71 97.5%
Construct = 2 13 0.3647 [0.2897; 0.4352] 53.42 77.5%
Test for subgroup differences (random effects model)
Q d.f. p-value
Between groups 0.69 2 0.7069
Notes: construct=0: purchase intention domestic, construct=1: willingness to buy domestic, construct=2:
reluctance to buy foreign
Notes: construct=0: purchase intention domestic, construct=1: willingness to buy domestic, construct=2: reluctance to buy foreign
Figure 5.25 Forest plot of PIWTB domestic with moderator construct
Study
Fixed effect model Random effects model
Heterogeneity: I2 = 92%, τ2 = 0.0357, p < 0.01 construct = 0
construct = 1
construct = 2 Fixed effect model
Fixed effect model
Fixed effect model Random effects model
Random effects model
Random effects model
Heterogeneity: I2 = 89%, τ2 = 0.0255, p < 0.01
Heterogeneity: I2 = 97%, τ2 = 0.0685, p < 0.01
Heterogeneity: I2 = 78%, τ2 = 0.0172, p < 0.01 Shimp & Sharma 1987
Shimp & Sharma 1987 Shimp & Sharma 1987 Shimp & Sharma 1987 Parts & Vida 2013 Parts & Vida 2013
Huang et al. 2008 Nguyen et al. 2008 Wang & Cheng 2004 Zeugner−Roth et al. 2015 Zeugner−Roth et al. 2015 He & Wang 2015
Suh & Kwon 2002 Suh & Kwon 2002 Huang et al. 2010 Nijssen & Douglas 2004 Nijssen & Douglas 2004 Rose et al. 2009 Rose et al. 2009 Rose et al. 2009 Rose et al. 2009 Douglas & Nijssen 2003 Selli & Kurniawan 2014 Parker et al. 2011 Mostafa 2010
When analyzing the moderators, the year the study was conducted was able to account for significant between group differences. Especially recent studies have shown relatively uniform effect sizes and effect sizes lower than what has previously been found. This could indicate a trend to lower levels of ethnocentric consumers’ preference for domestic products, and could to be further examined in future research.
Table 5.39 Analysis of PIWTB domestic for moderator year Test for subgroups (random effects model)
k COR 95%-CI Q I²
Yearcoded = 0 4 0.3901 [0.2702; 0.4982] 18.08 83.4%
Yearcoded = 2 9 0.1984 [0.1344; 0.2607] 33.95 76.4%
Yearcoded = 1 12 0.4280 [0.3348; 0.5129] 82.28 86.6%
Test for subgroup differences (random effects model)
Q d.f. p-value
Between groups 19.19 2 < 0.0001
Notes: Yearcoded=0: study from 1987-1999; Yearcoded=1: study from 2000-2010; Yearcoded=2: study from 2010-2017
As in other studies, the selection method used was also a significant between group moderator.
In the case of selection, this is in part due to the relatively high number of different methods used. Quota samples, which are often chosen to reflect the total population (Zeugner-Roth et al. 2015), report the lowest weighted average effect size, followed by random sampling. Other sampling methods employed showed higher results, but were also less frequently employed, and founded assumptions about a systematic difference can therefore not be made.
Table 5.40 Analysis of PIWTB domestic for moderator selection Test for subgroups (random effects model)
k COR 95%-CI Q I²
Selection = 2 4 0.3901 [0.2702; 0.4982] 18.08 83.4%
Selection = 5 6 0.2275 [0.1486; 0.3035] 19.71 74.6%
Selection = 0 9 0.3202 [0.2156; 0.4174] 58.68 86.4%
Selection = 4 1 0.6200 [0.5754; 0.6609] 0.00 -
Selection = 1 3 0.4263 [0.3590; 0.4892] 1.16 0.0%
Selection = 9 2 0.3046 [0.0162; 0.5463] 7.19 86.1%
Test for subgroup differences (random effects model)
Q d.f. p-value
Between groups 92.09 5 < 0.0001
Notes: Selection=0: Random sampling, Selection=1: Convenience sampling, Selection=2: Mail list, Selection=3: Panel, Selection=4: Semi-random sampling, Selection=5: Quota-sampling; Selection=9: N/a
Interestingly, when looking at the CETSCALE score, the effect size was highest for studies with lower scores, and lowest for the highest scores, although only one study fell in this cluster.
High effect sizes were also reported for studies with medium-high CET scores, which falls into what is expected.
Table 5.41 Analysis of PIWTB domestic for moderator CETtype Test for subgroups (random effects model)
k COR 95%-CI Q I²
CETtype = 0 7 0.4027 [0.2676; 0.5223] 92.98 93.5%
CETtype = 4 6 0.1955 [0.0947; 0.2923] 36.23 86.2%
CETtype = 3 10 0.3755 [0.2856; 0.4588] 41.32 78.2%
CETtype = 2 2 0.3369 [0.1388; 0.5091] 4.53 77.9%
Test for subgroup differences (random effects model)
Q d.f. p-value
Between groups 9.43 3 0.0241
Notes: CETtype=0: 17 items, CETtype=2: 11-16 items, CETtype=3: 6-9 items, CETtype=4: 2-5 items, CETtype=9: N/a
In addition, characteristics of participants and the number of items used in the CETSCALE also explained between group variance, at a lightly wider significance level of p<0.05. Hereby, students showed higher weighted average effect sizes than the general population, and the full 17-item scale also produced the highest weighted average effect sizes. Since high positive correlations of consumer ethnocentrism and willingness to buy foreign are expected as per definition of consumer ethnocentrism, these findings undermine the reliability of CETSCALEs with fewer items. Exact results of these moderator analyses can be found in Appendix D8.