From: Household demand and supply for clean groundwater in the Mekong Delta, Vietnam
Explanatory variable | Coefficient | t -value | R 2 | Number of observations | |
---|---|---|---|---|---|
No interaction effect | Â | Â | Â | Â | |
 Constant | 0.853 | 5.028*** |  |  | |
  Sex |  |  |  |  | |
   Female | - | - |  |  | |
   Male | 0.053 | 1.746* |  |  | |
  Age |  |  |  |  | |
   ≤40 years | - | - |  |  | |
   41 to 60 years | −0.118 | −1.622ns |  |  | |
   ≥61 years | −0.17 | −1.869* |  |  | |
  Education |  |  |  |  | |
   High school and above | - | - |  |  | |
   Primary school | −0.098 | −1.741* |  |  | |
   Secondary school | −0.057 | −1.423ns |  |  | |
  Occupation |  |  |  |  | |
   Other careers | - | - |  |  | |
   Farmers | 0.019 | 1.156ns |  |  | |
  Residence |  |  |  |  | |
   1996 to 2005 | - | - |  |  | |
   ≤1975 | −0.181 | −1.86* |  |  | |
   1976 to 1985 | −0.1 | −1.571ns |  |  | |
   1986 to 1995 | 0.025 | 1.743* |  |  | |
  Family number |  |  |  |  | |
   ≤3 persons | - | - |  |  | |
   4 to 5 persons | 0.041 | 1.591ns |  |  | |
   6 to 7 persons | 0.039 | 1.906* |  |  | |
   ≥8 persons | 0.058 | 1.719* |  |  | |
  Income |  |  |  |  | |
   ≤2 million VND | - | - |  |  | |
   2 to 5 million VND | −0.062 | −2.256** |  |  | |
   >5 million VND | −0.195 | −2.561** |  |  | |
Interaction effect | Â | Â | Â | Â | |
 Income |  Year of taking up residence |  |  |  |  |
  2 to 5 million VND |   ≤1975 | 0.107 | 1.591ns |  |  |
  2 to 5 million VND |   1976 to 1985 | −0.163 | −1.649* |  |  |
  2 to 5 million VND |   1986 to 1995 | −0.326 | −2.151** |  |  |
  >5 million VND |   ≤1975 | 0.106 | 1.344ns |  |  |
  >5 million VND |   1976 to 1985 | 0.092 | 1.356ns |  |  |
  >5 million VND |   1986 to 1995 | −0.408 | −2.986*** |  |  |
 | 0.210 |  | |||
 | 233 |