3.1. Descriptive Statistics
The objective of this study was to evaluate the discrete as well as the mutual interplay between farm production diversity and market access in influencing household dietary diversity. We have used primary data collected through a cross-sectional household survey in Gergera watershed, in eastern Tigray, northern Ethiopia. Data was collected from four sub-districts/kushets of the Gergera watershed. The detailed report from the descriptive statistics is presented in Table 1, below. The 120 households were selected from the subdistrict Damaino, 116 from Geter Haiki Mesihal, 84 from Degaabur, and 76 from Gergera. The gender-based proportions of the surveyed households are 290 male-headed households to 106 female heads. The mean age of the heads was 54.05 years, and the mean household size was 5.11 members. The average household dietary diversity score (HDDS) in the study area was 5.86 food groups per day per household (Table 1), while the mean farm production diversity was 3.48 food groups per year. The farm production diversity score shows a difference across genders of the household heads: male-headed households’ mean annual farm production diversity (PDS) was 3.70. Female-headed households’ mean annual farm production diversity level was 2.90 food groups. The mean monthly frequency of food market visits for all households was 3.03. Male-headed households made more frequent food market visits, with a mean of 3.13 times in 30 days, compared to female-headed households, with a mean of 2.75 times in 30 days. Households’ frequency of food market visits across subdistricts reveals a mixed association with households’ proximity to the market centre.
Subdistrict Geter Haiki Mesihal has the shortest mean walking time to the food market at 27.17 minutes, with a mean frequency of food market visits of 3.63; this is followed by Gergera, with a mean walking distance of 42.37 minutes and a slightly higher rate of 3.83 food market visits per month (Table 1). Residents of Damaino and Degaabur, the third and the fourth remotest subdistricts (a mean travel time of 82.42 and 149.88 walking minutes, respectively) made considerably less visits to the market, at 2.84 and 2.13 visits, respectively (Table 1).
Examining the third market access measurement variable, (Table 1), the results show that absence from the market demonstrates mixed association with proximity to the market. Residents of Dega’abur, the remotest subdistrict, demonstrate a mean of 5.11 days, while those in Geter Haiki-Mesihal, the closest to the market, had a mean of 4.77 days (Table 1). Those at an intermediate distance did not form a pattern: residents of Damaino reported the longest absence from food markets, with a mean of 7.76 days, while those in Gergera had the shortest absence from the market, at 3.77 days on average. Gender-wise, female-headed households experience longer absence from food purchases, with an average of 7.20 days, compared to male-headed households, with a mean of 6.26 days of absence (Table 1).
Table 1: Summary statistics for selected socioeconomic characteristics.
|
HDDS
|
PDS
|
Freq. food market visits
(in 30 days)
|
days of absence from market
|
Proximity to market
(In walking minutes)
|
Age
|
Family size
|
Education
|
Rainfed
Land size
(In Tsimad)
|
Irrigable land size
(In Tsimad)
|
GENDER
|
|
|
|
|
|
|
|
|
|
|
Female: N
|
106
|
106
|
106
|
106
|
106
|
106
|
106
|
106
|
106
|
106
|
Mean
|
5.53
|
2.90
|
2.75
|
7.20
|
75.75
|
51.58
|
3.42
|
0.37
|
0.77
|
0.22
|
|
|
|
|
|
|
|
|
|
|
|
Male: N
|
290
|
290
|
290
|
290
|
290
|
290
|
290
|
290
|
290
|
290
|
Mean
|
5.99
|
3.70
|
3.13
|
6.26
|
71.8
|
54.96
|
5.73
|
1.54
|
1.33
|
0.32
|
MARITAL STATUS
|
|
|
|
|
|
|
|
|
|
|
Divorced: N
|
46
|
46
|
46
|
46
|
46
|
46
|
46
|
46
|
46
|
46
|
Mean
|
5.50
|
2.96
|
2.98
|
7.02
|
62.93
|
50.07
|
2.87
|
0.37
|
0.74
|
0.2
|
|
|
|
|
|
|
|
|
|
|
|
Married: N
|
287
|
287
|
287
|
287
|
287
|
287
|
287
|
287
|
287
|
287
|
Mean
|
6.00
|
3.71
|
3.15
|
6.12
|
72.46
|
54.3
|
5.81
|
1.6
|
1.32
|
0.33
|
|
|
|
|
|
|
|
|
|
|
|
Single: N
|
2
|
2
|
2
|
2
|
2
|
2
|
2
|
2
|
2
|
2
|
Mean
|
6.50
|
2
|
1.50
|
9.00
|
120
|
25
|
3
|
0
|
0.5
|
0.12
|
|
|
|
|
|
|
|
|
|
|
|
Widowed: N
|
61
|
61
|
61
|
61
|
61
|
61
|
61
|
61
|
61
|
61
|
Mean
|
5.48
|
2.87
|
2.59
|
7.89
|
80.66
|
56.85
|
3.57
|
0.16
|
0.86
|
0.23
|
SUB-DISTRICTS
|
|
|
|
|
|
|
|
|
|
|
Geter Haki Mesihal: N
|
116
|
116
|
116
|
116
|
116
|
116
|
116
|
116
|
116
|
116
|
Mean
|
6.06
|
3.69
|
3.63
|
4.77
|
27.17
|
56.49
|
5.26
|
1.66
|
1.23
|
0.3
|
|
|
|
|
|
|
|
|
|
|
|
Damaino N:
|
120
|
120
|
120
|
120
|
120
|
120
|
120
|
120
|
120
|
120
|
Mean
|
5.82
|
3.42
|
2.84
|
7.76
|
82.42
|
49.76
|
5.08
|
1.11
|
1.26
|
0.46
|
|
|
|
|
|
|
|
|
|
|
|
Gergera N:
|
76
|
76
|
76
|
76
|
76
|
76
|
76
|
76
|
76
|
76
|
Mean
|
6.03
|
3.82
|
3.84
|
3.77
|
42.37
|
57.92
|
5.24
|
1.49
|
1.03
|
0.35
|
|
|
|
|
|
|
|
|
|
|
|
Degaabur N
|
84
|
84
|
84
|
84
|
84
|
84
|
84
|
84
|
84
|
84
|
Mean
|
5.51
|
3
|
2.13
|
5.11
|
149.88
|
53.32
|
4.82
|
0.56
|
1.11
|
0.00
|
TOTAL: N
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
Mean
|
5.86
|
3.48
|
3.03
|
6.49
|
72.86
|
54.05
|
5.11
|
1.23
|
1.18
|
0.3
|
Source: authors’ own computation from survey data collected in Sep. – Oct. 2020.
Gender-wise evaluation of the summary statistics in Table 1 demonstrates that male household heads have a higher average age, compared to female- heads, at 54.96 and 51.58 years, respectively; higher family size, at 5.73 to 3.42 persons; more years of schoolings, at 1.54 to 0.37; bigger rainfed farmland size, 1.33 to 0.77 hectares; and bigger irrigable landholding size, 0.32 to 0.22 hectares. Overall, these results show a dominance of male heads of households in all the parameters examined in Table 1.
3.2. Simple Statistical Analysis
3.2.1. Independent Relationship between Farm Production Diversity and Household Dietary Diversity
In Figure 2 mean Farm Production Diversity Score (PDS) is graphed on the X-axis, and the average values of household dietary diversity score (HDDS) on the Y-axis. The graph shows the independent relationship between the two variables. The visualization indicates that there is a positive non-linear relationship between farm production diversity and household diversity which can be divided into two stages of returns. The linear and LOWESS fit confirm that there is a positive return in the early stages of increasing farm production diversity, followed by diminishing returns to each additional unit of farm production diversity in the intermediate and later stages. A closer look at Figure 2 depicts that at the initial stage, additional food group production leads to a greater increase in HDDS.
Figure 2: Discrete Relationship between Farm Production Diversity and Household Dietary Diversity
At the intermediate stage, the rate of increase in HDDS diminishes for every additional PDS level; and gets flatter at later stages about 5 PDS levels and beyond.
3.2.2. Independent Relationship between Market Access and Household Dietary Diversity
In Figure 3 (A-C) a set of graphs are presented to examine the independent influence of market access on household dietary diversity. The three different graphs are used to examine the results and compare if there are significant differences when different measures of market access are used.
Figure 3A shows a distinct relationship between households’ frequency of food market visits and their level of household dietary diversity. The household dietary diversity is treated as a dependent variable, on the Y-axis, and the frequency of food market visits (FMV), on the X-axis. The graph shows that every additional market visit positively contributes to the household diet. Contrary to the pattern we observed on the PDS, the FMV shows a smaller rate of additions to the HDDS at the initial stages, and the rate of contribution increases with more market visits. A closer observation of the graph suggests that a certain level of market visits can achieve the maximum HDDS, beyond which each marginal visit brings little or no addition, but without turning negative Figure 3B depicts that recent market visits bring diverse foods to rural smallholder households. Market-day diets are more diverse than other days. Household dietary diversity diminishes as the number of days since a market visit increases. This is a factor for most of the surveyed households who live in rural areas, where there is limited electricity coverage and hence limited food preservation technologies. Households may purchase perishable foods that need to be consumed fresh, such as meat, milk, vegetables, and fruits.
Another interesting phenomenon revealed in Figure 3B is that when households attend food markets regularly (when their absence rate is small), they enjoy higher HDDS levels. However, a longer absence rate leads to lower but not zero HDDS: other food sources (for most households, primarily own-production) fill the gap in the absence of food purchases.
In Figure 3C we have presented another measure of market access, proximity to the market measured in walking minutes. Average proximity to the market is on the X-axis and average HDDS on the Y-axis. The graph indicates an inverse relationship between HDDS and proximity to the market: longer walking minutes adversely impact HDDS. Following the LOWESS fit, Figure 3C has also its own unique features. Close proximity to market is associated with higher HDDS but there is little difference among households living within 50 walking minutes radius. The downward trend in the middle of the graph shows that the remoter residents suffer from lower household dietary diversity levels. The horizontal line at the end of the graph (bottom right, which is visible in LOWESS fit) signals that after a certain remoter distance, the negative influence of remoteness on HDDS will be negligible. Accordingly, little or no change in HDDS is expected due to further increased distances if the households reside beyond 95 walking minutes from the food markets, in our study area.
3.2.3. Joint Relationship between Market Access and Farm Production Diversity
The joint interplay between farm production diversity and market access in influencing household dietary diversity is graphically examined in Figure 4A-C which graphs PDS against the three market access measures used in this study. Figure 4A shows that farm production diversity encourages households to make more food market visits but only up to a certain optimal point. As depicted in Figure 4A, the frequency of food market visits sharply increases with an increase in farm production diversity level at the initial stages with a lower rate of increase in visits at later stages.
Figure 4B graphs PDS (x-axis) against days of absence from markets (y-axis), and not surprisingly shows an inverse relationship compared with Figure 4A. This figure shows that more regular market attendance is associated with higher farm production diversity levels. However, there is little association beyond PDS levels of 5 or above. The final comparison, Figure 4C, shows the association between households’ proximity to markets and their level of farm production diversity. Farm production diversity is higher in households closer to the markets than in remote areas. The relationship implies that proximity to food markets encourages households to pursue more diverse farm production, while remoteness discourages farm production diversity.
Overall, we find that market access has a strong positive influence on farm production diversity. This result is contrary to the expectation that households in remote areas tend to diversify to compensate for inability to make food purchases due to limited access to the market.
3.3. Econometrics Results
The Poisson estimation evaluates the discrete and joint influence of farm production diversity and market access on household dietary diversity. Results are shown in Table 2. We have established two sets of models: the first set (Columns 1 to 4) is used to evaluate the discrete influence of farm production diversity (PDS) and the three market access measures (frequency of food market visits (FMV), absence from market (AM), and proximity to market (PM)) on household dietary diversity (HDDS). The second set of models in Table 2 (Columns 5 to 10) shows the joint influence of farm production diversity and the three market access measures on household dietary diversity.
Later in Table 3, HDDS is explained by the combination of the PDS, the three market access measures, and other socioeconomic factors. The results in Table 2 and Table 3 are presented in terms of marginal effects of the coefficients at the mean, from Poisson regressions.
3.3.1. The Independent Influence of Farm Production Diversity and Market Access on HDDS
The output in Table 2 Column 1 shows that the discrete influence of farm production diversity on household dietary diversity is positive and significant. This result is similar to previous findings based on various approaches such as Kumar et al. (2015); Jones et al. (2014); Romeo et al. (2016); Tesfaye and Tirivayi (2020); Muthini et al. (2020a). An additional unit of farm production diversity increases HDDS by 0.285 food groups, significant at a 1% level.
Independent evaluation of the three market access measures on HDDS is examined in Columns 2 to 4. All the three market access measures show a highly significant association with HDDS at a 1% level. However, the magnitude and direction of their influence is different. The frequency of food market visits has positive and higher magnitude of influence, compared to the remaining two market access measures. This finding is similar to the results obtained using panel data from Uganda by Morrissey et al. (2024). Every additional food market visit increase HDDS by an average of 0.452 food groups, (Column 2). Households’ absence from the market (AM) and proximity to market (PM) show negative influence with magnitudes of -0.011 for AM, (Column 3) and -0.004 for PM, (Column 4). The results indicate that household dietary diversity declines by an average of 0.11 food groups, if the household is absent from the market for 10 days.
Table 2: Poisson estimation of the influence of farm production diversity (PDS) and market access on HDDS
Household Dietary Diversity Score/ HDDS
|
Column (1)
|
Column (2)
|
Column (3)
|
Column (4)
|
Column (5)
|
Column (6)
|
Column (7)
|
Column (8)
|
Column (9)
|
Column (10)
|
Production Diversity Score/PDS
|
0.285***
|
|
|
|
0.205***
|
0.223***
|
0.271***
|
|
|
|
|
(0.037)
|
|
|
|
(0.038)
|
(0.038)
|
(0.037)
|
|
|
|
Frequency of food market visits
|
|
0.452***
|
|
|
0.338***
|
|
|
|
|
|
|
|
(0.058)
|
|
|
(0.059)
|
|
|
|
|
|
Absence from market
|
|
|
-0.011**
|
|
|
-0.088***
|
|
|
|
|
(In number of days)
|
|
|
(0.004)
|
|
|
(0.015)
|
|
|
|
|
Proximity to Market
|
|
|
|
-0.004***
|
|
|
-0.003***
|
|
|
|
(Walking minutes)
|
|
|
|
(0.001)
|
|
|
(0.001)
|
|
|
|
Frequency of visits X PDS
|
|
|
|
|
|
|
|
0.070***
|
|
|
(Interaction)
|
|
|
|
|
|
|
|
(0.007)
|
|
|
Absence X PDS
|
|
|
|
|
|
|
|
|
-0.012**
|
|
(Interaction)
|
|
|
|
|
|
|
|
|
(0.004)
|
|
Proximity X PDS
|
|
|
|
|
|
|
|
|
|
0.000
|
(Interaction)
|
|
|
|
|
|
|
|
|
|
(0.000)
|
Observations
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
396
|
Table 2 presents the marginal effects after Poisson estimation. The dependent variable is the household dietary diversity score, based on the 12 food groups. The models were estimated using Poisson model. The coefficient estimates are shown in column (1) to (4), robust standard errors in brackets. * p<0.05, ** p<0.01, *** p<0.001.
Source: authors’ own computation from survey data collected in Sep. – Oct. 2020.
Likewise, every additional 10 walking minutes farther from the market leads to an average of 0.04 food groups lower levels of HDDS.
3.3.2. The Independent Influence of Farm Production Diversity and Market Access on HDDS
The other key objective of this study is to examine the joint interplay between farm production diversity and market access on rural smallholder household dietary diversity. The output for the joint treatment of the variables is presented in Table 2, (Columns 5 to 10). The joint influences are estimated in two categories of models. The first category (Columns 5 to 7) evaluates the PDS pairing with each of the three market access measures. The second category (Columns 8 to 10) examines the interaction (multiplication) between the PDS and each of the three market access measures.
Evaluation of the joint interplay in Columns 5 to 7 of Table 2 reveals a positive but lower magnitude of influence, 0.205 for farm production diversity and 0.333 for the frequency of food market visits, compared to the results in Columns 1 and 2 (treated independently). However, the result confirms a combined positive influence of the PDS and the FMV on HDDS.
The joint estimation of farm production diversity and absence from the market in Table 2 (Column 6) indicates a lower magnitude of the PDS, 0.223, and a higher negative influence of absence from the market, -0.088, on HDDS, significant at 1% level. Conversely, the household’s proximity to the market shows a -0.003 influence on HDDS. Bergau et al. (2022) have also found a -0.001 magnitude of farmers’ travel time on HDDS in Ethiopia, which is close to this finding. The magnitude of the impact of PDS on HDDS in Table 2 has reduced from 0.285 (Column 1) to 0.271 (Column 7). This is possibly due to the negative effect of remoteness on PDS. The result is also supported by the visualization presented in Figure 4C above. One important point is that market access’ magnitude of influence measured in the frequency of food market visits is higher than in travel time as in Bergau et al. (2022). This indicates that how market access is measured affects its magnitude of influence (Muthini et al., 2020b).
Table 2 (Columns 8 to 10) depicts the interaction (multiplication) between the PDS and the three market access measures in examining their joint interplay. In Table 2 (Column 8), the magnitude of the interaction between PDS and the frequency of food market visits becomes 0.070, which is positive and significant at the 1% level. This value suggests a positive interaction between the two. The high magnitude of the coefficient of the FMV in different models, its partial derivative on HDDS, and using the effect plotting technique, the result indicates that the joint effect is altered by the households’ frequency of food market visits. This implies that keeping all other factors constant, where PDS and FMV are in operation, the frequency of the food market visits determines the level of household dietary diversity. The results reaffirm that the joint interplay between the frequency of food market visits and farm production diversity enhances smallholder household dietary diversity.
The interaction between PDS and absence from food markets (AM) is found be negative (-0.012), and significant at a 1% level, (Column 9). This suggests that these two variables have an inverse relationship. However, when both are simultaneously in operation, the household’s length of absence from food markets determines the HDDS. This means a household with a relatively high farm production diversity is likely to have a low level of dietary diversity due to its low food market attendance rate. Table 2 (Column 10) also shows the interaction between PDS and household proximity to the market. The relationship is insignificant. This insignificance might be associated with the lower consistency and weak predictive capability of proximity to the market as a measure of market access. Similar arguments have been made by Chegere & Stage (2020), and Usman & Haile (2022).
Overall, examination of the joint interplay between PDS and FMV reveals that frequent food market visits combined with greater farm production diversity, reinforce one another in improving household dietary diversity. A recent study conducted in Uganda comes to a similar conclusion, stating that “there are benefits to smallholders that come from a combination of crop diversity and market engagement” Morrissey et al. (2024, p.11).
Our study highlights the importance of considering the frequency of food market visits as an alternative measure of market access in understanding household dietary diversity. The results provide insights into the complex interplay of farm production diversity and market access in influencing household dietary diversity. This intuition can inform policies and interventions designed to improve market access and household dietary diversity in rural areas.
3.3.3. Estimation of the PDS and Market Access Alongside Control Variables
After estimating the influence of the PDS and FMV on HDDS separately, we regressed them together with smallholder household and socioeconomic characteristics as presented in Table 3. This can identify other influencing factors that might have been omitted in previous estimations in Tables 1 and 2. Moreover, it helps to test the robustness and stability of the key explanatory variables across different models. There are 6 models estimated using the Poisson regression and their marginal effects are indicated in Table 3. Columns 1 to 3 indicate the joint interplay among the PDS, the three alternative market access measures, and other selected socioeconomic variables. Columns 4 - 6 take the interaction of the PDS with the three market access measures and the control variables.
Table 3: Marginal effects after Poisson estimation:
The influence of farm production diversity, market access, and control variables on household dietary diversity.
Household dietary diversity score (HDDS)
|
-1-
|
-2-
|
-3-
|
-4-
|
-5-
|
-6-
|
|
HDDS
|
HDDS
|
HDDS
|
HDDS
|
HDDS
|
HDDS
|
Production diversity Score/PDS
|
0.208***
|
0.198***
|
0.255***
|
|
|
|
|
(0.037)
|
(0.037)
|
(0.038)
|
|
|
|
Frequency of food market visits
|
0.332***
|
|
|
|
|
|
|
(0.068)
|
|
|
|
|
|
Absence from market
|
|
-0.095***
|
|
|
|
|
(In number of days)
|
|
(-0.017)
|
|
|
|
|
Proximity to market
|
|
|
-0.003
|
|
|
|
(Walking minutes)
|
|
|
(0.002)
|
|
|
|
Frequency X PDS
|
|
|
|
0.066***
|
|
|
(interaction)
|
|
|
|
(0.008)
|
|
|
Absence X PDS
|
|
|
|
|
-0.010***
|
|
(Interaction)
|
|
|
|
|
(0.005)
|
|
Proximity X PDS
|
|
|
|
|
|
0.001***
|
(interaction)
|
|
|
|
|
|
(0.000)
|
Marital Status
|
|
|
|
|
|
|
Divorced
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
|
(.)
|
(.)
|
(.)
|
(.)
|
(.)
|
(.)
|
Married
|
0.184
|
-0.003
|
0.238
|
0.245
|
0.264
|
0.162
|
|
(0.49)
|
(0.377)
|
(0.468)
|
(0.469)
|
(0.437)
|
(0.463)
|
Single
|
1.387***
|
1.367***
|
1.485***
|
1.434***
|
1.765***
|
1.211**
|
|
(0.386)
|
(0.324)
|
(0.428)
|
(0.384)
|
(0.373)
|
(0.523)
|
Widowed
|
-0.013
|
0.036
|
0.102
|
0.032
|
0.12
|
-0.057
|
|
(0.27)
|
(0.263)
|
(0.265)
|
(0.263)
|
(0.265)
|
(0.271)
|
Sub-district
|
|
|
|
|
|
|
Geter Haiki Mesihal
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
|
(.)
|
(.)
|
(.)
|
(.)
|
(.)
|
(.)
|
Damaino
|
-0.621***
|
-0.001
|
-0.036
|
-0.083
|
0.031
|
-0.246
|
|
(0.183)
|
(0.142)
|
(0.15)
|
(0.196)
|
(0.156)
|
(0.16)
|
Gergera
|
-0.128
|
-0.114
|
0.018
|
-0.015
|
0.013
|
-0.041
|
|
(0.198)
|
(0.173)
|
(0.18)
|
(0.184)
|
(0.179)
|
(0.189)
|
Degaabur
|
-0.819***
|
0.164
|
0.038
|
0.167
|
0.189
|
-0.217
|
|
(0.223)
|
(0.173)
|
(10.175)
|
(0.299)
|
(0.185)
|
(0.187)
|
Gender
|
|
|
|
|
|
|
Female
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
|
(.)
|
(.)
|
(.)
|
(.)
|
(.)
|
(.)
|
Male
|
0.018
|
0.109
|
-0.018
|
-0.066
|
-0.048
|
0.007
|
|
(0.416)
|
(0.300)
|
(0.398)
|
(0.396)
|
(0.369)
|
(0.387)
|
Education level
|
0.044*
|
0.031
|
0.040*
|
0.042*
|
0.038*
|
0.041
|
|
(0.024)
|
(0.022)
|
(0.023)
|
(0.023)
|
(0.022)
|
(0.025)
|
Age
|
-0.004
|
-0.003
|
-0.003
|
-0.005
|
-0.003
|
-0.001
|
|
(0.005)
|
(0.005)
|
(0.005)
|
(0.005)
|
(0.005)
|
(0.005)
|
Family size
|
0.033
|
0.024
|
0.021
|
0.021
|
0.011
|
0.060*
|
|
(0.033)
|
(0.032)
|
(0.033)
|
(0.033)
|
(0.033)
|
(0.033)
|
Rainfed farmland holding size
|
0.047
|
-0.003
|
-0.056
|
-0.016
|
-0.064
|
0.108
|
(In tsimad= 1/4 hectare)
|
(0.062)
|
(0.057)
|
(0.060)
|
(0.061)
|
(0.060)
|
(0.063)
|
Irrigable landholding size
|
0.595***
|
0.495***
|
0.320**
|
0.446***
|
0.275*
|
0.568*
|
(In tsimad= 1/4 hectare)
|
(0.150)
|
(0.136)
|
(0.137)
|
(0.138)
|
(0.140)
|
(0.151)
|
Observations
|
396
|
396
|
396
|
396
|
396
|
396
|
Table 3 presents the marginal effects after Poisson estimation. The dependent variable is the household dietary diversity score, based on the 12 food groups. The models were estimated using Poisson model. The coefficient estimates are shown in column (1) to (4), robust standard errors in brackets. * p<0.05, ** p<0.01, *** p<0.001.
Source: authors’ own computation from survey data collected in Sep. – Oct. 2020.
The results in Table 3 show that PDS regressed with selected control variables positively and significantly influences HDDS, ranging from 0.198 to 0.225 food groups. There are small changes in coefficient values compared with Table 2 which could be associated with the compensating effects of the included control variables: nonetheless, the direction and level of significance observed in Table 2 is sustained. Similarly, the frequency of food market visits with an estimated coefficient of influence of 0.332, and that of the absence from the market, -0.095, show only minor differences compared to their respective magnitude in Table 2, and the direction and level of significance are still maintained. However, although proximity to the market has the same magnitude of influence as was observed in Table 2, it is not significant in Table 3. Again, this could be another indicator for the proximity to market’s weak predictive power compared to the other two measures examined in this paper.
The results for the interaction variables in Table 3 also exhibit similar features to those reported in Table 2. An exception to this is the coefficient of the interaction between PDS and proximity to the market, which becomes significant at the 1% level in Table 3. This again suggests that there is an issue of stability in using proximity to the market as a measure of market access compared to the alternative market access measures examined.
In addition to exploring the relationship between household dietary diversity and some selected control variables, we found a few other socioeconomic variables that influence household dietary diversity. Examining marital status, the finding shows that a single household head positively influences HDDS. However, caution should be taken in handling this result, because the number of single household heads in our survey was minimal (See Table 1). The other influencing factor is the geographic locations of the households, specifically the sub-district in which they are located. Damaino sub-district residents on average consume 0.621 lower food groups, (significant at 1%), than those in Geter Haiki-Mesihal, the reference category. Similarly, residents of Degaabur consume 0.819 food groups with lower household dietary diversity than households in Geter Haiki-Mesihal, significant at 1%. The education level of household heads positively affects household dietary diversity, at the 5% significance level. The other influencer of HDDS in our study areas was the size of household irrigable farmland. An additional one Tsimad (a quarter of a hectare) of irrigable land ownership leads to an average increase in HDDS by 0.320 – 0.595 food groups, significant at 1% -5% levels.
3.3.4. Robustness checks
The robustness of our findings is checked by applying different model fit tests. The first is the Likelihood Ratio (LR) Test, used to compare the fit of the Poisson model against alternative models such as the negative binomial regression to check for overdispersion. The result (LR test alpha = 0: chibar2(01) = 0.000; Prob > = chibar2 = 1.000) indicates that there is no evidence of overdispersion, and the Poisson model used is a good fit. In addition, we run the Pearson goodness of fit to see if our data fits the Poisson regression model. The Pearson test result chi2 = 83.31748; Prob > chi2(382) = 1.000, shows that the fitness of the data to our model is good.