Table 5.
Effect Direction Plot of the Included Studies Grouped by Outcome and Label Type.
| Study ID | Study design | Sample size | Product type | Presentation format (logo or text) | Intervention format (info or claim | Certification scheme | Supporting hypothesis | SS |
|---|---|---|---|---|---|---|---|---|
| Outcome: actual purchase | ||||||||
| Label type: organic | ||||||||
| Aerni et al. (2011) | Experimental study | 3275 | Corn bread | T | C | N | Y -▲ | Y |
| Daunfeldt and Rudholm (2014) | Natural experiment | NR | Olive oil, flour, coffee | L | C | Y | Y -▲ | Y |
| Zanoli et al. (2015) | CE | 427 | Apples | L | C | Y | Y -▲ | Y |
| Label type: GHG emissions | ||||||||
| Aoki and Akai (2013) | CE | 212 | Oranges | T | I | N | Y -▲ | Y |
| Brunner et al. (2018) | Field experiment | 2524 | Meat, fish, salads | L | I | N | Mixed◀▶ | Y |
| Elofsson et al. (2016) | Field experiment | NR | Milk | L+T | C+I | Y | Y -▲ | Y |
| Pelletier et al. (2016) | Experimental study | NR | Various products | L | I | N | Y -▲ | Y |
| Label type: environmentally sustainable | ||||||||
| Hallstein and Villas-Boas (2013) | Quasi-experimental study | NR | Seafood | L | C | N | Y -▲ | Y |
| Label type: mixed | ||||||||
| Vlaeminck et al. (2014) | Field experiment | 150 | Food market products | L+T | I: GHG emissions; water use; land use | N | Y -▲ | Y |
| Wuepper et al. (2019) | CE | NR | Coffee | L+T | C: organic; water use | N | Y -▲ | Y |
| Outcome: hypothetical purchase | ||||||||
| Label type: organic | ||||||||
| Aoki et al. (2017) | CE | 3,395 | Rice | T | C | Y | Y -▲ | Y |
| Apaolaza et al. (2017) | Experimental study | 90 | Wine | L+T | C | N | Y -▲ | Y |
| Bauer et al. (2013) | Online experiment | 630 | Cereals | L+T | C | Y | Y -▲ | Y |
| Carlucci et al. (2017) | CE | 800 | Oysters | T | C | Y | Y -▲ | Y |
| Delmas and Lessem (2017) | DCE | 883 | Wine | T | C | Y | Y -▲ | Y |
| Gumirakiza et al. (2017) | CE | 819 | Peaches, eggplants, and yellow squash | T | C | Y | Y -▲ | Y |
| Harwood and Drake (2018) | ACBC | 1,163 | Milk | T | C | Y | Y -▲ | Y |
| Hoogland et al. (2007) | Field experimental study | 371 | Chicken, milk, salmon | L | C | Y | Y -▲ | Y |
| Kim et al. (2013) | lab acceptance test | 208 | Milk | T | C | N | Y -▲ | NR |
| Mondelaers et al. (2009) | choice preference experiment | 529 | Carrots | T | C | N | N -▼ | N |
| Silva et al. (2017) | Pre-post experimental study | 126 | Dark chocolate | L+T | C | Y | Y -▲ | NR |
| Label type: environmentally sustainable | ||||||||
| Aizaki et al. (2013) | CE | 624 | Milk | L | C | Y | Y -▲ | Y |
| Blend and Van Ravenswaay (1999) | Experimental study | 893 | Apples | T | C | Y | Mixed◀▶ | Y |
| Brach et al. (2018) | Online experiment | 101 | Various food products | T | C | Y | N -▼ | Y |
| Cho (2014) | Experimental study | 203 | Apple pie and frozen pizza | T | I | N | Y -▲ | Y |
| Cho and Baskin (2018) | Experimental study | 53 | Cereals & canned sausage | T | I | N | Y -▲ | Y |
| Durham et al. (2012) | Experimental study | 1500 | Coffee | T | C+I | Y | Y -▲ | Y |
| Fernandez-Polanco et al. (2013) | DCE | 169 | Seabream | T | C | N | Y -▲ | Y |
| Gosselt et al. (2019) | Experimental study | 180 | Coffee | L+T | C | N | Y -▲ | Y |
| Hoek et al. (2017) | CE | 944 | Rice, meat, tomato | L+T | C+I | N | N -▼ | N |
| Risius et al. (2017) | CE | 447 | Trout | L+T | C | Y | Y -▲ | Y |
| Rokka and Uusitalo (2008) | CBCA | 330 | Functional drinks | T | C | Y | Y -▲ | Y |
| Label type: GHG emissions | ||||||||
| Panzone et al. (2011) | Experimental study | 1,377 | Cola, milk, meat, butter | T | I | N | N -▼ | N |
| Shuai et al. (2014) | CE | 873 | Agri-food products | L | C | N | NR | NR |
| Label type: other claim (pesticide use) | ||||||||
| Borin et al. (2011) | Online experiment | 329 | Apples | T | I | N | Y -▲ | N |
| Label type: mixed | ||||||||
| Akaichi et al. (2016) | CE | 399 | Bananas | L+T | C+I, C: organic; I: carbon footprint | Y | Y -▲ | Y |
| Caputo et al. (2018) | CE | 257 | Chicken | L+T | C+I, C: organic; I: carbon footprint | Y | Y -▲ | Y |
| Grebitus et al. (2013) | CE | 1,551 | Ground beef | T | I: GHG emissions; water use | N | Y -▲ | Y |
| Seo et al. (2019) | CBCA | 173 | Spinach | T | C: organic; Pesticide-free | N | Y -▲ | Y |
| Wuepper et al. (2019) | CE | NR | Coffee | L+T | C: organic; water use | N | Y -▲ | Y |
Note. L = logo; T = text; C = claim; I = information; NR = not reported; SS = statistically significant; GHG = greenhouse gas; ▲ = statistically significant positive effect; ▲ = not statistically significant positive effect; ▼ = not statistically significant negative effect; ◀▶ = both statistically significant positive and negative effects observed (mixed result).