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Field
Experimental Design (Public)
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Before
Treatment assignment (timing of price subsidies): The experiment uses a randomised design to assign the timing of payments at disposal sites for the 400 participating waste collectors. 200 collectors randomly assigned to the treatment 1 group receive subsidy payments at disposal sites during the first week of the intervention. The remaining 200 collectors are the control group during the first week. At the end of the week, the collectors assigned to the control group during the first week start receiving the payment for a period of 1 additional week, while the treatment 1 collectors stop receiving the payment during this second week. We track outcomes daily for both groups via different tools: a daily form administered by enumerators, registries upon payments at disposal sites, and a self-developed smartphone application where collectors register their waste collection transactions.
Intervention details: In both weeks, the treatment consists of payments at disposal sites of different quantities. At dumpsites, collectors may receive 10 or 15 GHS daily. At formal waste transfer stations, collectors are eligible to claim a subsidy payment of 100 GHS daily. The intervention thus induce exogenous variation in the relative prices of disposal sites, and more specifically, it makes formal solid waste disposal substantially cheaper in the city. The payment will be conducted via mobile money daily.
We will estimate ITT effects on formal disposal at transfer stations (primary outcome) and on additional outcomes potentially affected by this choice (i.e. number of customers, revenues, collection location, collection prices). We will do this aggregating at treatment period (week 1 and week 2 are the 2 periods), but also by plotting raw shares over intervention days. During baseline we will gather information on disposal site choice during the last 7 days and report daily event studies (using the first day of receiving payments as reference period) for formal disposal as the outcome variable.
We will estimate ITT effects on whether any soft power from leaders or dumpsite operators is a reason for the choice of disposal site. Finally, we will test for heterogeneity of the ITT effect on disposal at transfer station by pre-existing distance between collection area and transfer stations.
We will use assignment to the treatment as an instrument for disposal fees and estimate TOT effects to understand the passthrough of lower disposal fees on number of customers and collection prices.
We will use the assignment to treatment as an instrument for route profits and estimate the taste parameters governing collectors’ route choices in a collection-disposal site discrete choice framework via GMM. This will complement the current structural approach we use to estimate our full model of waste collection and disposal.
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After
Treatment assignment (timing of price subsidies): The experiment uses a randomised design to assign the timing of payments at disposal sites for the 400 participating waste collectors. 200 collectors randomly assigned to the treatment 1 group receive subsidy payments at disposal sites during the first week of the intervention. The remaining 200 collectors are the control group during the first week. At the end of the week, the collectors assigned to the control group during the first week start receiving the payment for a period of 1 additional week, while the treatment 1 collectors stop receiving the payment during this second week. We track outcomes daily for both groups via different tools: a daily form administered by enumerators, registries upon payments at disposal sites, and a self-developed smartphone application where collectors register their waste collection transactions.
Intervention details: In both weeks, the treatment consists of payments at disposal sites of different quantities. At dumpsites, collectors may receive 10 or 15 GHS daily. At formal waste transfer stations, collectors are eligible to claim a subsidy payment of 100 GHS daily during the first wave and 200 GHS during the second wave. The intervention thus induce exogenous variation in the relative prices of disposal sites, and more specifically, it makes formal solid waste disposal substantially cheaper in the city. The payment will be conducted via mobile money daily. The variation across the two waves serves induces additional variation in disposal prices, conditioning on the intervention characteristics (i.e. engaging with the survey team, or any other factors that differ from a pure price drop at transfer sites)
We will estimate ITT effects on formal disposal at transfer stations (primary outcome) and on additional outcomes potentially affected by this choice (i.e. number of customers, revenues, collection location, collection prices). We will do this aggregating at treatment period (week 1 and week 2 are the 2 periods), but also by plotting raw shares over intervention days. During baseline we will gather information on disposal site choice during the last 7 days and report daily event studies (using the first day of receiving payments as reference period) for formal disposal as the outcome variable.
We will estimate ITT effects on whether any soft power from leaders or dumpsite operators is a reason for the choice of disposal site. Finally, we will test for heterogeneity of the ITT effect on disposal at transfer station by pre-existing distance between collection area and transfer stations.
We will use assignment to the treatment as an instrument for disposal fees and estimate TOT effects to understand the passthrough of lower disposal fees on number of customers and collection prices.
We will use the assignment to treatment as an instrument for route profits and estimate the taste parameters governing collectors’ route choices in a collection-disposal site discrete choice framework via GMM. This will complement the current structural approach we use to estimate our full model of waste collection and disposal.
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