**Table 3. Description of outcome variables**

|**Construct**|**Outcome variables**|**Measure**|
|---|---|---|
|Textbook<br>Availability|Received textbooks*|Dummy variable: 1 - if school received or collected<br>textbooks for new curriculum; 0-otherwise|
||Textbook-pupil ratio**|Number of textbooks available (for literacy course per<br>term) in the school divided by number of relevant grade<br>students enrolledinthe school|
||Receiving textbooks in 1<br>month|Dummy variable: 1 - if school received/collected<br>textbooks within 1 month after the books were available in<br>DEBS officeforpick-up; 0-otherwise|
|Tbk|Textbook transported to<br>school by DEBS|Dummy variable: 1 - if DEBS transported the textbooks to<br>school; 0-otherwise|
|extoo<br>delivery<br>mechanism|Collection of the books<br>from DEBS|Dummy variable: 1 - if school collected the books from<br>DEBS on their own; 0-otherwise|
||Collection of the books<br>from zone-center school|Dummy variable: 1 if school collected the books from<br>zone school on their own; 0 otherwise|

_Note:_ *For the pre-treatment (baseline), the study measured the availability of Grade 2 textbooks for a literacy course under the new curriculum that schools were supposed to receive after June 2016 when books became available in MoGE's warehouse. For post-treatment (end-line), the study measured the availability of Grade 4 textbooks for a literacy course under the new curriculum that schools were supposed to receive after October 2018 when books became available in MOGE's central warehouse. When schools reported receiving books for a specific grade before these dates and before DEBS’s reported receiving date, the books were considered as old curriculum books that were delivered late; this event was coded as not receiving new curriculum books. **For the textbook-pupil ratio, the study measured both old and new curriculum books delivered since 2015. This approach was chosen because schools did not keep separate records for old and newly published books.

# **Empirical Analysis Strategy**

In order to answer the first research question, descriptive statistics were analyzed. These include (i) textbook delivery and availability status based on the school and DEBS surveys in the baseline and the end-line; and (ii) regressing outcome variables, at baseline, on possible contributing factors, including measures for information and communication on textbook availability, school-level financial resources (PTA funds and education budget), and location (remoteness) of schools.

The second and third research questions were studied by conducting econometric analysis employing difference-in-difference estimation. Difference-in-difference captures changes in outcomes of the treatment and control groups before and after the treatment using the following equation: i 0 1T T 1 2T T 2 3P 4T T 1 ∙P 5T T 2 ∙P i i YY denotes the outcome variable for each individual school; “= ββ + ββ TT + ββ TT + ββ PPTT+ ββ _i_ TT” for two different periods and “PPTT+ ββ TT PPTT+ εε _t_ ” (Grade 2 textbooks for pre-treatment and Grade 4 textbooks for post-treatment). T T 1 and T T 2 are dummy variables of whether the school belongs to the first treatment group (school incentive group) or to the second YY treatment group (DEBS incentive group). P is post-treatment dummy variable and TT i is an idiosyncratic TT error term. PPTT εε The coefficients of the interaction terms, T T 1 ∙P and T T 2 ∙P ( 4 and 5), capture the impact of the school incentive scheme and of the DEBS incentive scheme on textbooks availability. For the estimation of difference-in-difference, the school-level fixed effect is used with TT PPTT TT PPTTP ββ and interaction terms ββ and other time-varying variables, including dummy variables for the information and communication on PPTT 9