4.2 The Impact of Buffer Stock Operations on Well-Being
As a first step to the 2SLS analysis, we use the Durbin–Wu–Hausman (DWH) test for endogeneity to formally evaluate the hypothesis that OWB is exogenous. A Durbin (score) chi
2 of 11.010 and Wu-Hausman F-statistic of 10.091 are significant at 1%. The significant test statistic implies that the variable, OWB, is endogenous. Similarly, the regression-based endogeneity test (DWH) presented in Appendix Table
7 shows that the coefficients of −3.0325 and 4.049 of the residuals for the OWB and SWB, respectively, are both significant at 1%. These results indicate the presence of endogeneity, justifying the use of the 2SLS estimation technique. The results of the first stage regression of the 2SLS estimation are presented in Table
3. The results in Table
3 present the regressions to obtain the predicted values of NAFCO and OWB for the subsequent (second state) estimation of the 2SLS estimation. Note that we included age squared
(Age2) in the objective well-being (OWB) and subjective well-being regression, as most empirical studies of subjective well-being find
Age2 as a determinant (Blanchflower & Oswald,
2008; Senasu & Singhapakdi,
2017). The community's satisfaction is also captured by safety living in the community and relationship with community members, which were used in indexing OBW.
Table 3
First-stage 2SLS regressions to obtain predicted values for NAFCO and OWB
Gen | 0.064 (0.057) | −0.101 (0.118) |
Age | −0.044*** (0.011 | 0.015 (0.023) |
Age2 | 1.235*** (0.251) | −0.396 (0.542) |
Mar | −0.036 (0.060) | 0.093 (0.126) |
HS | −0.028*** (0.010) | 0.057*** (0.021) |
Education | −0.047* (0.025) | 0.011 (0.053) |
Lstock | −0.004*** (0.001) | 0.003 (0.002) |
Lntscost | 0.159*** (0.053) | 0.039 (0.113) |
Secjob | −0.191*** (0.034) | −0.067 (0.060) |
Revmz | 0.090*** (0.013) | 0.417*** (0.029) |
Middle | 0.020 (0.021) | −0.156 *** (0.043) |
Ext | 0.428*** (0.050) | 0.629 (0.104) |
Market | −0.091*** (0.028) | 0.026 (0.058) |
NAFCO | – | 0.630*** (0.103) |
Cons | −8.551*** (1.410) | 5.941*** (3.096) |
F-stat | 28.39*** | 35.00*** |
R2 | 0.532 | 0.610 |
Adj. R2 | 0.514 | 0.595 |
RMSE | 0.347 | 0.7523 |
No. obs | 342 | 338 |
The summary statistics of the first stage equation show Cragg and Donald Wald statistics (minimum eigenvalue) of 64.82 and 22.00 for the
NAFCO and OWB models, respectively, compared to the critical value of the Wald test of 19.93, which is significant at 10% leading us to reject the null hypothesis that the instruments are weak. Furthermore, the first-stage
F-statistics for the regressions in Table
3 confirm the instruments' validity: the significant F-statistics values are greater than 10 (see Stock & Yogo,
2005). In addition, the tests of overidentifying restrictions, the Sargan (2.34) and Basmann (2.28) statistics, are not significant at 10% indicating the instruments are not sufficiently related to well-being. As such, the Cragg and Donald Wald, Sargan, and Basmann tests further confirm that extension and market access are appropriately valid instruments for predicting
NAFCO.
Tables
4 and
5 present the estimated models for the OWB and the SWB, respectively. the results for the OLS estimations are presented in addition to the 2SLS estimates for comparison (see Tables
4 and
5), although the OLS estimations are expected to produce bias and inconsistent estimates. Therefore, we restrict the rest of this discussion to the results for the 2SLS model. The overall goodness of fit statistics (Wald Chi
2 and adjusted R-squared) for both the OWB and SWB for the 2SLS models in Tables
4 and
5 show a good fit.
Table 4
The impact of buffer stock operations on objective well-being (OWB). Dependent variable: OWB
NAFCO (Treatment) | 0.626*** (0.101) | 1.213*** (0.216) |
Gender | −0.091 (0.118) | −0.130 (0.288) |
Age | 0.016 (0.022) | 0.046 (0.070) |
Age2 | −0.408 (0.529) | −1.238** (0.616) |
Mar | 0.121 (0.124) | 0.114 (0.0129) |
HS | 0.057*** (0.021) | 0.073*** (0.022) |
Edu | 0.009 (0.052) | 0.023* (0.665) |
Lstock | 0.002 (0.002) | 0.006*** (0.002) |
Lntscost | 0.035 (0.112) | −0.084 (0.122) |
Secjob | −0.060 (0.060) | −0.030 (0.062) |
Revmz | 0.417*** (0.029) | 0.348*** (0.037) |
Middle | −0.161*** | −0.179*** (0.045) |
Constant | 6.067** (3.044) | 11.337*** (0.3621) |
F (Wald chi2) | 42.63*** | 473*** |
R2 | 0.614 | 0.567 |
Adj. R2 | 0.600 | – |
RMSE | 0.722 | 0.745 |
No. obs | 342 | 338 |
Table 5
The impact of buffer stock operations on subjective well-being (SWB). Dependent variable: SWB
OWBa | 0.987*** (0.097) | 1.033*** (0.295) |
Gen | −0.408* (0.218) | −0.437** (0.215 |
Age | 0.069* (0.040) | 0.070* (0.040) |
lnAge2 | −1.599* (0.940) | −1.622* (0.934) |
Mar | 1.520*** (0.230) | 1.471*** (0.227) |
Edu | 0.111 (0.096) | 0.098 (0.094) |
HS | 0.077** (0.038) | 0.070* (0.039) |
Lstock | 0.007* (0.004) | 0.008** (0.004) |
Lntscost | 0.115 (0.205) | 0.098 (0.206) |
Secjob | 0.325** (0.110) | 0.328*** (0.111) |
Revmz | −0.141** (0.068) | −0.149 (0.152) |
Middle | −0.286*** (0.079) | −0.265*** (0.086) |
Constant | 9.806* (5.357) | 9.853** (5.242) |
F (Wald chi2) | 24.31*** | 203.60*** |
R2 | 0.470 | 0.467 |
Adj. R2 | 0.451 | – |
RMSE | 1.336 | 1.305 |
No. obs | 342 | 338 |
In discussing the results, we first start with the NAFCO-effect on objective well-being (OWB) and then turn to the mediated NAFCO effect on subjective well-being (SWB). For model 2, it should be noted that though
Lstock, and
Middle are not significant in the OLS estimation, after accounting for possible endogeneity, the variables became significant, and the magnitudes of their coefficients increased. The magnitude of the coefficient of
Lstock, for instance, increased from 0.002 to 0.006 and became significant at 1%. Similarly, the
NAFCO variable's coefficient in the OLS estimate increased from 0.626 to 1.213 in the 2SLS estimate, showing a downward bias of the OLS estimates presented in Table
4, as expected a priori based on initial tests (see Appendix A2).
The 2SLS estimates in Table
4 show that the coefficient of
NAFCO is 1.213 and significant at 1%, indicating a positive impact of the
NAFCO initiative on the OWB of smallholder farmers. To compute how much of OWB the
NAFCO farmers had more than the non-NAFCO farmers in percentage terms, we compare the treatment coefficient (ATT) to the mean objective well-being level (OWB), 6.14, (see Table
2) of the non-NAFCO farmers, we see that the OWB of NAFCO farmers is about 20%
2 more than the non-NAFCO farmers. In other words, participation in NAFCO improves OWB by 20%.
The 2SLS estimates in Table
4 further show that the control variables
HS, Edu, and Lstock, all have a positive and significant association with OWB, providing further assurance that these variables are appropriate as control variables. Interestingly, the positive and significant coefficient of
Lstock, 0.006, indicates that livestock production affects OWB positively. A possible explanation for this finding may be that income from livestock sales and improved access to protein from livestock meat enhances the food and nutrition security of farmers (Smith et al.,
2013), bolstering their wealth and eventually well-being. The 2SLS model in Table
4 also shows that
Age2 significant at 5% indicating that households with younger heads and older ones have a better OWB compared to middle age ones. The district-level control variables,
Middle and
Revmz, are highly significant as shown in Table 4 indicting the extent of intermediaries’ activities and the perceived level of relevance of maize to the district economy are appropriate as control variables.
3
Table
5 presents the results of modeling the relationship between SWB and OWB. Comparing the OLS and the 2SLS estimates show that both estimates are similar to those of the 2SLS, with the OLS results being biased downwards. The 2SLS estimates results show that the OWB estimated coefficient of 1.033 is significant at 1%, indicating a strong association between OWB and SWB. The results mean that NAFCO has a mediating and indirect effect on SWB through OBW. This corroborates Western and Tomaszewski (
2016) findings, who reported a strong association between SWB and OWB among the disadvantaged working class in Australia. They note that improvement in the OWB of households is critical for improvement in the SWB. Importantly, comparing the coefficient of OWB, 1.033, to the mean assessed SWB levels of the non-NAFCO farmers (6.70) in Table
2, the results indicate that the SWB of NAFCO farmers is about 15%
4 more than the non-NAFCO farmers. Hence, overall, our results support Tsai's (
2009) general findings that price stabilization influences SWB. In the case of the observed smallholder farmers, price stabilization through buffer stock initiative improves SWB indirectly through the improvement of OWB.
In Table
5, we note a negative coefficient for gender, suggesting that women-headed households are more likely to be satisfied with life than men-headed ones, a finding consistent with Zweig (
2015). Even though women, compared to men, are more likely to have lower incomes, less educated, and these inequalities could cause women to have lower SWB compared to men, this is not always the case. Research has shown that’women’s aspirations in life are lower than’men’s and are, therefore, easily satisfied with their life compared to men' (Clark,
1997). These aspirations are formed from culture and social norms, which play an essential role in individuals' well-being: a phenomenon real for women in Ghana (see, for example, Zweigh 2015; Plagnol & Easterlin,
2008). The
Age2 term
, which captures the possibility of a non-linear relationship between the household’s head’s age and SWB, is negative and significant, implying that the relationship between age and SWB is U-shaped. This result means that SWB is more for young people, decreases with age to reach a minimum, and increases afterward in later life stages (Blanchflower & Oswald,
2008). Similar findings are reported by Senasu and Singhapakdi (
2017) for Thailand.
The estimated coefficient for
marriage has a positive and significant effect on SWB, suggesting that married smallholder farmers are happier than their unmarried counterparts. The reason for this finding could be that marriage promotes better health by increasing the likelihood of couples helping each other (Stack & Eshleman,
1998). Research also shows that marriage helps encourage spouses to follow a healthy diet and gives emotional support to each other to reduce stress and pressure. Besides, marriage pools two partners' resources together for household use, providing each other with income security (Asiedu & Folmer,
2007).
The variable HS (household size) coefficient is positive and significant, implying that farmers with larger households have better SWB than those with smaller sizes. This result is in line with the finding of Shui et al. (2020), documenting a positive association between household size and SWB. Though larger poor households are expected to be constrained by the low resource endowment in providing for their basic needs, they are satisfied because of the love, care, and prestige of a large family.
The 2SLS estimates in Table
5 further show that the
level of engagement in secondary jobs has a negative association with SWB. Kuykendall and Tay (
2015) explain that engagement in multiple jobs increases the workload and stress levels, lowering the SWB of farmers. Juggling between multiple careers/roles has been linked to stress-related health outcomes such as blood pressure, among others (Sumra & Schillaci,
2015). Similarly, the significant negative estimate of
middle (-0.265), implies that the activities of intermediaries in the communities are detrimental to both OBW and SWB of farmers. We find intermediaries as rent-seekers who exploit poor farmers by offering lower prices for their produce.