In the last video, we looked at the water demand behavior of household with pipe connections. In this video, we will examine the water demand behavior of households without pipe connections. With sources outside the home. Since almost all households in high income countries have piped water in their home, our focus in this video will be exclusively on households in developing countries. I will start with the findings from the classic work by Gilbert White, David Bradley and Ann White. These data were collected between 1966 and 1968 at 34 study sites in Kenya, Tanzania and Uganda. This figure shows mean per capita water use by housing class. There're three main findings that have stood the test of time. First, if you bring piped water inside the home, water use increases dramatically. As soon as someone has to carry water from a source outside the home to the house, water use falls dramatically. Even if the source is a near short distance away. Second, households that live in most high rise apartment buildings use much less water than households in low density neighborhoods. This is largely because residents of high rise buildings do not have outdoor water uses. Third, poor rural households with water sources outside the home, use very little water. The data reported in draws of water, showed that many poor rural households with water sources outside their homes, use 10 liters per capita per day or less. Such low levels of water use are still common in many poor, rural communities in Africa and South Asia. This next figure shows the relationship between the cost of water per liter and the amount of water used by households living in different types of housing. Note that this is the raw data one would need to estimate the demand relationship between price and quantity used. There is no obvious relationship apparent in these data, but these cost per liter are very low. And this is a common problem in estimating water demand relationships. Because prices are low, we don't know what would happen to water use if prices were significantly increased because this has never happened in many places. The next two slides show the relationships between per capita daily water use and the distance water is carried from the home. This first slide shows the relationship for sampled households in two villages. Mutwot and Masii. Note the distance the water is carried can be considered a measure of the cost per liter. The data for these two villages seem to show that distance from the home does not affect the quantity of water used. But look carefully at the horizontal axes for these two villages. For the village shown in the left panel, most of the water sources are relatively close to households, within half a mile. For the village in the right panel, a few households are walking considerably farther, about two miles. And these few households are in fact using less water than households with sources closer to their homes. This next slide shows the effect of distance on per capita use more clearly. It is only when the distance to the water source becomes more than one mile away, that we see a decrease in per capita water use. This make sense in terms of trips per day. As distance increases beyond a certain point, it is physically not possible for one person to make more than one trip per day. Note how low per capita water use is for households with a water source more than one mile from their home. About five liters per capita per day. This next slide shows the relationship between mean per capita use and distance from source for urban households. Note that distance on the horizontal axis is now measured in feet, not miles. Because most urban households walk considerable shorter distances to water services outside the home, than households in rural areas. As in rural areas, the distance to the water source outside the home, does not have much effect on mean per capita water use, when the distances are relatively short. In this case, most households are within 1,200 feet of a source. At the right of the figure, a household collecting rain water and buying from water vendors. Both of these groups of urban households are using more water than households walking to sources outside their home. Although purchasing water from vendors is expensive, the vended water is delivered to the home and per capita water use is higher. Of course this comparison does not control for household income and other socioeconomic variables. To wrap up, when households must collect their water from outside the home, they use much less water than households with piped connections. Urban households without piped connections typically use much more water than rural households. Both because they usually have higher incomes and because sources outside the home are closer. Finally, household water use in poor rural villages where households must walk to collect water from outside the home is very low. In the next video, we're going to look at household demand for water quality improvements. Thanks for watching this video. [BLANK_AUDIO]
