The dependency ratio of a population is defined by the ratio of the number of materially and financially dependent people to the number of the people of working age (from 15 to 64 years). Dependants can be divided into two age groups either those too young or too old to work namely; those aged between 0 - 14 years and those older than 65 years. The dependency ratios as determined by the Population and Housing Census of 2005 have been divided into 5 bands. The lowest ratio is less than 60 dependants to 100 working age people while at the other extreme is a ratio of over 140 dependants to 100 wage earners corresponding to a ratio of 1.4:1.

The results of the Population and Housing Census of 2005 reveal that the average national dependency ratio declined by about 0.8% in the 10 years between 1995 and 2005. In 2005 for every 100 people of working age there were on average about 76 dependants. In the Lao PDR the dependency ratios differ in each province, each region and each area. A ratio of more than 1 i.e. where between 110 and more than 140 people depend on I00 working age people occurs in the south, in the central parts of the provinces of Savannakhet, Saravane, Sekong and Attapeu, and in the south of Champasack. This imbalance continues into the eastern mountainous parts of Khammuane, Borikhamxay, and the east of Vientiane, in Xiengkhuang, and Huaphanh and scattered in the east of Phongsaly. It is estimated that in about 20% of all districts more than 110 people depend on about 100 working age people. However, this does not necessarily mean hardship and lack of food because it is not clear how many of the children older than 6 - 8 years contribute to family income. In addition many older people contribute to the livelihood of households.

The lowest dependency ratio at the provincial level is observed in Vientiane Capital with only 46 dependants for every 100 persons of working age while in the provinces of Huaphanh, Xiengkhuang and Sekong the ratio is 1:1 or 100 dependants for every 100 working people. The map shows those regions with the lowest dependency rates are to be found in the central region in the south and the higher rates in the north. It is clear that in the developed plain areas especially in Vientiane Capital the dependency rate is low in comparison to that in the mountainous regions. The flat areas are better developed and work can be found more easily. If a large number of the population of working age have jobs then the dependency rate in that region is low. In the mountainous areas where the level of development is low the chance of employment is also low. There is also a loss of labour since workers migrate out to other districts especially to urban areas. Therefore, the number of older adults and children is high and has a significant effect on the dependency ratio in these mountainous regions.