Donald T. Lauria

A study of water vending and willingness to pay for water in Onitsha, Nigeria

Abstract Most people in Onitsha, Nigeria obtain their water from an elaborate and well-organized water vending system which is run by the private sector. About 275 tanker trucks collect water from private boreholes and sell it to households and businesses equipped with water storage facilities. Many of these households and businesses resell water by the bucket to individuals who cannot afford large storage tanks or who cannot be reached by the tanker trucks. During the dry season the private water vending system collects about 24-times as much revenue as the public water utility. On an annual basis, households in Onitsha pay water vendors over twice the operation and maintenance costs of a piped distribution system.

Water vending activities in developing countries: a case study of Ukunda, Kenya

Millions of people in developing countries obtain water from commercial vendors who deliver it to their homes, yet this phenomenon has received little attention from professionals in the water resources field. This paper describes a water vending system which is in operation in Ukunda, Kenya, a town of about 5000 people south of Mombasa. In this community 45% for water consumed by households is obtained from water vendors who deliver water in carts directly to peoples homes. The prices vendors charge for water are high, but vendors are not making exorbitant profits; hauling water manually is simply expensive. People in Ukunda spend about 9% of their income on vended water, which suggests that there are situations in which households are willing and able to pay substantial amounts of money for water even when traditional sources are readily available.

Household sanitation in Kumasi, Ghana: A description of current practices, attitudes, and perceptions

Abstract Over 1200 households in Kumasi, Ghana were interviewed in 1989 about their current sanitation practices, perceptions of existing sanitation conditions, expenditures, and their knowledge of improved sanitation options. The results of the survey and related research revealed an appalling and, from a public health perspective, dangerous situation. Households were generating about 25,000 cubic meters of waste per month, but only about 10% of it was removed from the city. The remaining 90% was left in the urban environment. In aggregate, households were spending about US

An optimization model for reducing typhoid cases in developing countries without increasing public spending.

75,000 per month to use the existing sanitation system (about 75% of which was spent for the use of public latrines). People in Kumasi were only spending about US

The Effect of Giving Respondents “Time to Think” on Tests of Scope: An Experiment in Calamba, Philippines

1.50 per capita annually for sanitation services, and, correspondingly, were getting very poor service. Households were quite open to the idea of simple, low-cost, on-site solutions to their sanitation problems.

Selecting Optimal Prices and Outpost Locations for Rural Vaccination Campaigns

This article considers the investment case for using the Vi polysaccharide vaccine in developing countries from two perspectives: reducing typhoid cases and limiting new health care spending. A case study is presented using data from South and Southeast Asia. The purpose of the paper, however, is to draw broad implications that may apply to developing countries in general. Typical consumer demand functions developed from stated preference household surveys in South and Southeast Asia are used to predict probabilities of adults and children purchasing typhoid vaccinations at different prices. These functions are incorporated in a formal mathematical model. Using data from the recent literature for South and Southeast Asia for typhoid incidence, Vi vaccine effectiveness, public cost of illness, and vaccination program cost, three mass vaccination policy alternatives are evaluated: charging adults and children different (optimal) prices, charging uniform prices, and providing free vaccines. Assuming differential pricing is politically feasible, different vaccine prices for children and adults would maximize the number of typhoid cases avoided from a mass vaccination program if the public sector faces a budget constraint on spending for the vaccination program. However, equal prices for children and adults produce very similar results, and they might be more readily accepted by the community. Alternatively, if vaccines are free, the number of cases is not significantly reduced compared to either pricing policy, but a large external financial contribution from government or donors would be required. A Monte Carlo simulation explores the effects of uncertain parameters on vaccination program outcomes.

Effect of travel distance on household demand for typhoid vaccines: implications for planning

The possible inability of respondents in contingent valuation surveys to offer higher willingness-to-pay amounts for a good or service that the survey researcher believes to be unambiguously better than another good or service has been termed the “embedding ” or the “part-whole” problem. Draft guidelines issued by the United States National Oceanic and Atmospheric Administration (NOAA) in 1994 for the use of the contingent valuation method to assess natural resource damages require that at least three split sample “tests of scope” be conducted to determine whether this embedding problem exists. If it does, the accuracy of the CV results is called into question. These “tests of scope” are to offer three different groups of respondents three valuation scenarios in order to see whether respondents value them differently. A “successful” experiment will increase one’s confidence that respondents are somehow “sensitive” to the specific good or service described, and are not valuing some other commodity or scenario. How one judges whether a test of scope has been successful (and thus the contingent valuation results can be used) is unclear.1 Nor did NOAA offer guidance on the appropriate procedures to use when carrying out tests of scope. Future research is clearly required on how best to implement tests of scope.

An Optimisation Model for Use of the Vi Polysaccharide Vaccine to Prevent Typhoid in Developing Countries

A contingent valuation survey (willingness-to-pay study) was conducted in 2004 to measure household demand for typhoid vaccines in a rural township in China with approximately 54,000 people living in 141 villages. The results showed that travel distance to vaccination sites and vaccination price affected the private demand for typhoid fever vaccinations. The number and location of vaccination outposts are thus important decision variables for a new vaccination campaign that is under consideration. This article develops and applies an optimization model for planning vaccination programs. The model determines what price to charge, how many vaccination outposts to use, where to locate them, and what capacities they need. The model uses demand information from the contingent valuation survey and cost information from similar vaccination campaigns in China and assumes that costs must be covered by user fees. The model determined that the number of outposts to use for maximizing coverage was fourteen, which would make average one-way travel distance for users about 0.6 km. The optimal vaccination price was USD 1.25, and about 87 percent of the population would be vaccinated. A suboptimal solution of the model showed that only 6 outposts instead of 14 would probably vaccinate about 83 percent of the population, and the price could be reduced to USD 0.83. The model is easy to use and solve and can be applied to different size regions.

The Economic Benefits of Surface Water Quality Improvements in Developing Countries: A Case Study of Davao, Philippines

Typhoid fever causes millions of illnesses and hundreds of thousands of deaths yearly. Vaccinations would mitigate this problem, but the users would probably have to pay some or most of the cost. Several willingness-to-pay studies have assessed the effect of price on private demand to provide a basis for financial planning of campaigns, but the effect of travel distance, which is a potentially important determinant of demand, has not been studied. This paper thus has two objectives: (i) conduct a willingness-to-pay survey to assess the effects of distance, price and other variables on the private demand for typhoid vaccinations in a rural township of China where a campaign is under consideration; and (ii) embed the demand function in a mathematical model to address three planning questions; should each village have its own clinic, would one clinic be best or should the number of clinics be something in-between? Private vaccine demand was found to depend on and be inelastic with respect to both price and travel distance. A 1-km increase in distance caused the number of vaccinations demanded to decrease the same as a

Household demand for improved sanitation services in Kumasi, Ghana: A contingent valuation study

0.5 increase in price. Thus, the marginal rate of substitution was