Table 2. Perceptions of risk and benefit, and attitudes towards the willingness to engage in risk mitigation behavior and factor loadings from principal component analysis.
| Scales and Items | M(SD) | Factor loadings | |
| General Risk Perception | |||
| 1 | What is your general estimate of the size of the problem caused by invasive non-native plants in Switzerland? | 3.99 (1.34) | |
| Benefits ; Cronbach's α (scale mean): 0.84 (3.74) | |||
| 2 | For my business, non-native plants are economically important. | 3.70 (1.74) | |
| 3 | It is easier to sell exotic plants than native species. | 3.51 (1.53) | |
| 4 | The choice of plants has to be complemented by non-native plants because native ones do not possess all of the properties desired by the customers. | 4.77 (1.43) | |
| 5 | New species and cultivars may improve biodiversity. | 3.40 (1.60) | |
| 6 | If I don't sell a non-native plant because of the risk it poses to the environment, my customers may buy it in another store. | 3.66 (1.75) | |
| 7 | To me, it is important to frequently offer my customers new species and cultivars. | 3.79 (1.60) | |
| 8 | The cultural value of a horticultural landscape is essentially dependent on new species and cultivars. | 2.97 (1.54) | |
| 9 | Non-native plants belong to our gardening culture. | 4.12 (1.59) | |
| Willingness to Engage in Risk Mitigation Behavior ; Cronbach's α (scale mean): 0.80 (4.08) | |||
| 10 | As long as one cannot rule out the possibility that a non-native plant will become invasive in Switzerland, a ban on the import of this plant should be imposed. | 3.36 (1.83) | 0.72 |
| 11* | In Switzerland, trade of non-native plants does not require legal regulations. | 2.96 (1.85) | 0.64 |
| 12* | There should be no restrictions on importation of non-native plants into Switzerland, as long as there is no evidence that these plants potentially become invasive in Switzerland. | 3.70 (1.82) | 0.65 |
| 13 | No plants should be allowed for import into Switzerland that have been shown to have been invasive in another country. | 4.50 (1.68) | 0.57 |
| 14 | Increase prices for plants that are included in the Black list (i.e. plants that had been listed by the Swiss Commission of Wild Plant Conservation to be invasive non-native plants in Switzerland, and that cause negative impacts in the context of biodiversity, health, and/or economy). | 3.00 (1.93) | 0.48 |
| 15 | Remove plants from my stock that are listed on the Black-list. | 4.64 (1.56) | 0.68 |
| 16 | Ban the sale of any non-native plant, until it has been shown that it does not pose a danger to humans or the environment. | 3.90 (1.73) | 0.76 |
| 17 | Inform customers about invasive non-native plant species. | 5.31 (1.03) | 0.62 |
| 18 | Promote the sale of native plants. | 4.73 (1.40) | 0.52 |
Note: Numbers vary from 608 to 622 because of missing data. Rating scales for item 1 went from 1 = ‘very small problem’ to 6 = ‘very big problem’, for items 2–13 from 1 = ‘not agree at all’ to 6 = ‘totally agree’, and for items 14–18 from 1 = ‘I cannot imagine at all’ to ‘I can imagine very well’.