*2.3. Data*

This study relied on a dataset originally obtained from a field survey conducted by the authors in March 2020 in two rural areas (Thieu Ngoc and Darsal) in Vietnam. The data that supported this study's findings are available from the corresponding author on reasonable request.

Due to the difficulty of obtaining a sufficient sample size using internet panels in rural areas of Vietnam, we conducted face-to-face surveys. We had the full cooperation of the local governmen<sup>t</sup> of both Thieu Ngoc and Darsal, and the opportunity to conduct face-to-face surveys in all households in both villages. We chose these two areas because the local population is mainly engaged in primary industries, especially farming. Therefore, they are typical rural villages where people live in the traditional Vietnamese way. The main crops are rice in Thieu Ngoc, and coffee in Darsal.

Thieu Ngoc is in the Thieu Hoa district of Thanh Hóa province in the North Central Coast region, while Darsal is in the Dam Rong district of Lam Dong province in the central highlands. As shown in Table 1, per capita income in Thieu Ngoc in 2018 was US\$1075, which is significantly lower than the US\$2093, US\$3036, and US\$1615 for the whole country, urban areas, and rural areas, respectively (General statistics office of Vietnam). Thus, per capita income in Thieu Hoa is lower than in most rural areas in Vietnam. On the other hand, the per capita income in Darsal in 2018 was US\$1753, which is nearly the same as all rural areas in Vietnam (US\$1615).


**Table 1.** Official statistics of Thieu Hoa and Darsal in 2018.

Note: The exchange rate was calculated at 0.000043 US\$/dong, which was the average exchange rate in 2018. Data were sourced from the local governments of Thieu Hoa and Darsal.

In the face-to-face survey, we attempted to ensure the accuracy of responses through translations and multiple checks by Vietnamese native speakers, as well as by providing extensive training to our field agents, in which they received consistent instructions directly from one of the authors. We originally had participants of 1824 and 3043 from Thieu Hoa and Darsal, respectively. After eliminating the subjects who responded with "I don't know/I don't want to answer this question" to questions regarding consumption and other subjects that were deemed invalid, 1250 and 2435 eligible subjects from Thieu Hoa and Darsal remained, respectively.

To understand the general details of Thieu Hoa and Darsal residents, we conducted the following questionnaire, as shown in Table 2.

Figure 1 shows the distribution of annual household income. The average annual household income is US\$6395, and the median is US\$4719.

Next, Figure 2 shows material possessions per household. Most households possess two or three motorcycles, while only a few own automobiles. Concerning home appliances, more than 90% of households own televisions and rice cookers, about 74% own refrigerators, less than 50% own washing machines, and only about 20% own air conditioners. Regarding personal computers and mobile phones, about 14% of households own personal computers, while more than 95% own mobile phones.

Figure 3 shows the degree of food self-sufficiency. We found that 43% of respondents answered 3 (quite frequently) and about 25% answered 4 (very frequently). This implies that many people in the sample do not spend all of their money on food, so they are able to buy other things or put money into savings.

Figure 4 shows the frequency of bartering with other neighborhood residents. It shows that more than 34% of respondents frequently barter with other neighborhood residents. As shown in Figure 5, typical bartering goods are food (34%), furniture (16%), and clothes (12%), implying that people in the areas barter a variety of material goods.

Table 3 shows the survey questionnaire used for the main analysis. Concerning consumption, we asked questions pertaining to total monthly household consumption and material consumption. Material consumption represents the household consumption of "goods" (electrical appliances, furniture, clothes, shoes, publications, and other sundries, excluding expenditure related to housing, cars, and motorbikes). Monthly household consumption expenditure includes not only expenditures on "goods", which we have defined above, but also expenditures on housing, cars, motorbikes, medical expenses, insurance, and education, among others. As shown in Section 2.2, in our empirical model, we divided total monthly household consumption into material consumption, defined above, and residual consumption, and focused on the relationship between material consumption and SWB, while controlling residual consumption in the empirical model.

**Figure 1.** Annual household income in Thieu Hoa and Darsal (US\$; N = 3685).

0 1 2 3+ <NA>

**Figure 2.** Material possessions per household (N = 3685).

**Figure 3.** Food self-sufficiency (N = 3685).

**Figure 4.** Frequency of bartering with neighborhood residents (N = 3685).

**Figure 5.** Type of goods bartered (N = 3685).




**Table 3.** Survey questionnaire for the main analysis.

Tables 4–6 show descriptive statistics for the survey questionnaire used for the main analysis. The average monthly household material consumptions are US\$179, US\$188, and US\$175; these distributions are shown in Figures 6–8, respectively. We found similar descriptive statistics for variables used for analysis and the distribution of monthly household material consumption among the overall sample and Subsamples.



**Table 5.** Descriptive statistics for overall sample for Subsample 1 (Attachment dummy = 1, N = 892).


**Table 6.** Descriptive statistics for overall sample for Subsample 2 (Attachment dummy = 0, N = 2689).


**Figure 6.** Monthly household material consumption for overall sample (US\$; N = 3685).

**Figure 7.** Monthly household material consumption for Subsample 1 (US\$, Attachment dummy = 1, N = 892).

**Figure 8.** Monthly householdmaterial consumption for Subsample 2 (US\$, Attachment dummy=0, N = 2689).
