Factors influencing farming households’ climate change adaptation strategies in Central Vietnam

PLOS One | https://doi.org/10.1371/journal.pone.0328058 July 10, 2025 7 / 22 The marginal effect of exogenous factors is given by: δj = Pj Xk = Pj [ βjk – ∑J–1 J=1 Pjβjk ] = Pj(βj – β) (4) The marginal effect measures the expected change in the probability of a particular choice being made for a unit change in the explanatory variable. The signs of the marginal effects and the corresponding coefficients could be different because the coefficients depended on the signs and magnitudes of all the other coefficients [61–64]. Table 1 described the variables expected to be included in the model to analyse factors affecting the choice of livelihood strategies to adapt to climate change of farming households. The adoption of these strategies was hypothesized to be influenced by demo- graphic and socio-economic characteristics, such as gender, age of the household head, household size, education level, farm size, annual income, and number of livestock and breeds owned; institutional factors, such as credit services, agri- cultural extension services, social networks, access to information and awareness of climate change. 2.3 Data collection and analysis This study employed both primary and secondary data sources to ensure comprehensive and contextually grounded analysis of the factors influencing climate change adaptation strategies among farming households. Primary data were collected through a combination of qualitative and quantitative methods. Specifically, focus group discussions and in-depth

interviews were conducted with local officials, commune leaders, and villagers to explore community-level perceptions and challenges associated with climate change adaptation. These methods were instrumental in contextualizing the research, refining the questionnaire design, and capturing localized knowledge and lived experiences that quantitative data alone could not fully reveal. The qualitative insights also informed the selection of variables for subsequent modeling and anal- ysis. In addition to field-generated data, secondary data were collected from several authoritative sources to complement Table 1. Description of explanatory variables in the model. No. Explanatory variables Code Expected signs Measurement 1 Gender of respondent GEN +/- 1: male 0: female 2 Household size SIZE +/- Continuous 3 Education level of respondent EDU +/- Continuous 4 Age of respondent AGE +/- Continuous 5 Household monthly income INC +/- Continuous 6 Farming experience EXP +/- Continuous 7 Percentage of soil salinity SAL +/- Continuous 8 Location of farmland POS +/- Continuous 9 Farmland area ARE +/- Continuous 10 Access information from the state INF + 1: yes; 0: no 11 Membership of the local associations MEM + 1: yes; 0: no 12 Access credit from policy banks CRE + 1: yes; 0: no 13 Participate in training courses TRA + 1: yes; 0: no Source: Study design (2024). https://doi.org/10.1371/journal.pone.0328058.t001