Intervention(s)
Prior to the price randomization, starting in July 2015, we `linearized' the water tariff schedule. At the time, the official schedule had three blocks: For consumption below 10 m3, the price was VND5,300 per m3, increased to VND7,200 per m3 for any consumption above 10 m3 and below 20 m3, and again to VND8,000 per m3 for any higher consumption. With the linearization, every household in the three villages was charged a uniform VND5,300 per m3 price and the water utility was reimbursed for the revenue loss relative to the block-price schedule. This linearized price schedule prevailed throughout the experiment, with randomized discounts applied at various points as described below. In June 2017, however, provincial authorities raised the water price to a uniform VND7,950 per m3, an increase which we passed on to all consumers and which was broadly announced by An Thinh. Throughout the experiment, the An Thinh water utility shared their administrative data on household water bills, which includes monthly water usage (in m3) and payment from July 2015 onward.
The actual price experiment started in January 2016, 6 months into the price linearization. The intervention consisted of offering households rebates on their (linearized) water price: 50 percent or 75 percent.