the IE is evaluating interventions that are _not_ financed by a Bank project. Clearly, when project and IE data are merged, IEs with missing project id are automatically dropped.

Data is organized according to the quarter of implementation of the project. As such, quarter 1 is the first quarter of project implementation after effectiveness for all projects in the sample, and it can correspond to different calendar quarters depending on when the project started. By construction, there are 1,135 observations in quarter 1 with observations falling monotonically to 32 projects in quarter 28 (Figure 2). This represents an unbalanced panel of projects in different quarters, with an average project duration of 15 quarters across the 2005:Q1 to 2011:Q4 period. This sample has a substantial amount of variation in project vintage and duration across quarters.

We use the period before midterm as the institutional benchmark. As argued above, the period before midterm is of great importance as this is when projects are substantially off track. These delays may force teams to “push out” disbursements during the later phase of the project to avoid losing funding. We define the subset of projects that have reached midterm and the subset of quarters up to that midterm (an institutional benchmark) as the set that allows us to reduce composition effects. As Figure 3 illustrates, this approach reduces the heterogeneity in project duration and vintage, making sector composition more stable.

# 3.C. DESCRIPTIVE STATISTICS

Projects in our panel span 11 sectors and all six regions of the World Bank. The largest sectors in number of projects are agriculture and rural development, and transport, while the largest region is Africa. IEs are represented in regions and sectors to varying degrees (see Figure 4 and Table 1). Noninfrastructure sectors are well represented, while infrastructure sectors are less so. The public sector governance sector is excluded, as it did not have any IEs in this period of time.<sup>13</sup> In Table 2, we present descriptive statistics for projects with and without IE. The next few paragraphs discuss the statistics in this table. Eighty percent of the projects are still active (that is, under implementation) and the rest have closed, with different vintages (or start years) being evenly represented in the sample. About half of all projects (52 percent) have reached midterm, typically at two-thirds of their planned life.<sup>14</sup> The median midterm falls on quarter 13, with more than 50 percent of projects reaching midterm between Q11 and Q16. On average, projects are in their fourth year of implementation (15 quarters) out of the five years (20 quarters) originally planned. In terms of duration and other project characteristics, no difference between project with and without IE is found to be statistically significant, with the exception of loan size. The average loan size for projects without IE is $109 million versus $149 million for projects with IE.

Regarding the outcomes of interest, total disbursements are higher for projects with IE. This is in line with the larger loan size for projects with IE. Moreover, projects with IE disburse more relative to

> 13 This has changed since then.

> 14 Midterm should happen about halfway in project implementation. In practice, this is scheduled at two-thirds into project implementation due to delays.

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