Table 1 List and description of variables used in regression models
From: IITA’s genebank, cowpea diversity on farms, and farmers’ welfare in Nigeria
Variable | Definition |
|---|---|
Dependent variables | |
\(d^{r}\) | Menhinick richness index for cowpea varieties grown |
\(d^{e}\) | Shannon evenness index for cowpea varieties grown |
\(d^{d}\) | Berger-Parker dominance index for cowpea varieties grown |
\(d^{c}\) | Herfindahl–Hirschman concentration index for cowpea varieties grown |
Anc | = 1 if the cowpea variety grown has a genebank ancestor and 0 otherwise |
Yield | Cowpea yield in kilograms (kg/ha) |
Consumption | Quantity of cowpea used for home food consumption, in kilograms (kg) |
Sale | Quantity of cowpea grain sold, in kilograms (kg) |
Independent variables | |
Household characteristics | |
Age | Age of the household head in years |
Sex | = 1 if the household head is male and 0 otherwise |
Education | Education of the household head in years |
Household size | Number of household members |
Experience | = 1 if the household has experience growing an improved cowpea variety and 0 otherwise |
Need credit | = 1 if the household head needs credit and 0 otherwise |
Pedigree information | |
Anc | = 1 if the cowpea variety grown has a genebank ancestor and 0 otherwise |
NumAnc | The number of genebank ancestors in the pedigree of the cowpea variety grown |
Farm characteristics | |
Size | Farm size in ha, using GPS |
Slope | Number of plots that are perceived as flat |
Soil fertility | Number of plots that are perceived as poor |
Distance to field | Distance to field from residence, in minutes |
Market characteristics | |
Distance to seed dealer | Distance to the nearest seed dealer in minutes |
Distance to village market | Distance to the village (local) market in minutes |
Distance to district market | Distance to the district (main) market in minutes |
Geographical zone | |
North East | = 1 if the household falls within the North East zone and 0 for the North West zone |