although it is to be expected that changes in per capita gdp and average income will tend to move together as shown in the surveys it is important to remember that these variables relate to different concepts also there are methodological differences that can widen discrepancies such as the type of income flows that are actually measured and geographic coverage some surveys cover only urban areas to name only the most important shortcomings to accomplish this the lowerincome household group was analysed a predominant pattern emerges across the episodes analysed this group s income declined more than that of the total group of households