| Estimating the conditional standard deviation of some living standard | 
| 
 | 
| The following figure shows a scatter plot of the beninese household expenditures for 1996 and 1999. | 
|  | 
| To show the conditional standard deviation of these expenditures: | 
| 
 
 | 
|  | 
| 
       | 
| One can normalise this standard deviation by the expected level of Y (the expected total expenditures in the final period at a given level for the initial period). To do this, select the option "Normalised by the expected value of Y" | 
| 
       | 
| 
 | 
| Instead of initial income, one can use average income of the household across the two years. | 
| 
       |