Experimental Design Details
The City/County anticipate allocating approximately $2-3 million per lottery “wave” of applications on paying back rent. Each wave will be open for approximately two weeks of applications. Funding amounts and application windows may be revised according to funding availability and the volume of applications.
Some applicants will not be entered into the lottery, based on a determination by the City/County that they are particularly at risk. At this time, having a pending eviction filing or utility shut-off notice is a risk factor that would cause households to not be entered into the lottery and to receive immediate assistance on back rent. Similarly, the City/County is conducting bulk negotiations with large landlords to clear back rent from all delinquent tenants. Households excluded from the back rent lottery, who do receive back rent, may be entered into the future rent lottery.
After a household wins the back rent lottery, screeners hired by the City/County will confirm eligibility. Households who are not eligible may be contacted by the City/County to update their eligibility materials or removed from the lottery. They may then be re-entered in the lottery for a subsequent wave. Therefore, because winning a lottery does not perfectly determine assignment, we will use an instrumental variables design, wherein winning a lottery is an instrument for ever receiving assistance.
Households that apply but do not win the back-rent lottery will automatically be re-enrolled in a subsequent lottery. This means that people who apply early are very likely to eventually receive assistance, since they will have many chances to win a lottery. Insofar as early and late applicants may differ on observable and unobservable demographic characteristics likely to be related to our outcomes of interest, our primary specification will adjust for treatment probability, e.g. by including calendar time fixed effects for the “wave” of the lottery in which they apply. Within each wave, treatment status is randomly assigned and unrelated to observable and unobservable applicant characteristics. Because different demographic groups have different odds of winning the lottery (because of the lottery weights, explained above), primary specifications may additionally include fixed effects for these demographic groups or will be appropriately re-weighted.
At this time, we do not intend to automatically re-enroll households who lose the future rent lottery into the future rent lottery.
We first send landlords the offer for back rent. Among landlords who accept the back rent offer, we will additionally enter those tenants who indicated they will have trouble paying future rent into a weighted lottery for the future rent offers. The future rent lottery will take place several weeks after the initial back rent lottery. As above, note that any household that receives back rent (including people excluded from the back rent lottery) can be entered into the future rent lottery.
The City/County also anticipate spending approximately $500,000 to $1 million per lottery “wave” of applications on paying future rent. Therefore, approximately 20–50% of applicants who indicate they are eligible for future rent will receive a future rent offer.
Primary specification. The primary specification will use IV to assess the impact of receiving back or future rent on the desired outcome, using the lottery assignment as an instrument for receiving assistance. We will adjust for differences in treatment probability (which could vary by application wave and//or because some demographic groups will receive priority weights). In our primary or secondary specification, we may include baseline covariates selected using a robust selection procedure (e.g., double/debiased machine learning) for power.
The exclusion restriction is that the only way lottery assignment affects outcomes is via receiving back or future rent assistance. A possible confound (which we do not view as especially likely) is that receiving an offer itself changes outcomes, even if aid is not delivered. For instance, landlords who decline aid may feel guilty and forgive some (but not all) rent. For this reason, we will also present the reduced form of offering assistance on outcomes.
An alternative strategy to obtain the effect of future rent may use the specific future rent offer bundle to instrument for the landlord’s take-up decision. In particular, some landlords will randomly receive more generous future rent offers and (we conjecture) be more likely to take up. The random variation in the offer bundle can be used to instrument for the effect of future rent given take-up.
Given that households will be randomized into back rent and future rent, a specification that çaptures both forces could jointly instrument for the endogenous variables of receiving back and future rent relief, using the vector of back and future rent offers.
The effects on landlords can be measured in a similar way as for tenants. However, to study the effects on landlords, we may amend the primary specification as follows. Due to random selection, some landlords may have more tenants who receive aid. We can therefore run landlord-level regressions, using the random variation in the number or share of tenants who receive aid offers to instrument for aid receipt.
Secondary specification. Because people who enter the lottery early are very likely to win (given we will run multiple waves of the lottery), we may explore specifications where we consider the date of treatment to be randomly assigned. In these specifications, we may study the outcomes defined as of the date when they win the lottery. For instance, we may study whether households who win the lottery early have reductions in eviction filings or increases in credit scores earlier than those who win the lottery later. If almost all households ultimately win the lottery, the secondary specification may be promoted to the primary specification.
The unit of analysis in all specifications with tenant outcomes will be household-level. Because the level of random assignment is the household, we cluster standard errors for specifications with tenant outcomes at the household level.
Treatment effect heterogeneity. We are unsure of the demographic heterogeneity that we will be powered to explore, given the composition of applications. It is particularly interesting and natural to examine treatment effect heterogeneity by the size of the assistance offered. Therefore we intend to study:
- Treatment effects by back rent owed.
- Treatment effects by the rent to income ratio (or similar ratio).
- We may study whether tenant demographics affect the landlord’s propensity to accept rental assistance offers. Demographics that may affect the landlord’s propensity to accept include tenants’ gender, race, income, and age (and, for instance, whether the tenant’s demographics are the same or different from the landlord’s).
- Heterogeneity in the effects of receiving assistance by demographic characteristics is likely to be secondary. However, we may present treatment effects by gender, race, age, and household composition.
We intend to amend this discussion as data become available but before analysis.