# Data

- Our main data source is the official public procurement data portal of North Macedonia https://e <u>nabavki.gov.mk/. We follow the data collection, standardization and quality assurance procedures</u> outlined in Fazekas et al (2024) and further refined on https://opentender.eu/. We first annotate the source website and identify all the relevant fields required for the analysis as well as create enumerations for data fields which are published in Macedonian. For example, enumerating national procedure types to commonly used procurement procedure types such as open procedure or supply types such as goods, works or services. We then built a dedicated web crawler to scrape the HTML pages of all the available procurement publications such as call for tenders, contract awards, contract amendments and cancellations. We then use the publications’ identification numbers to correctly match the publications with each other to create a single record in our dataset that accurately represents the complete tendering process from publishing the call for tenders to the contract award (including any amendments). We also flag tenders that were canceled at any point during the tendering process to be excluded from the analysis. The collected raw data of the matched publications is then parsed into a standard data structure<sup>1</sup> allowing for consistent analysis over time within the same country, but also comparisons across countries.

We manually validate the collected data fields against the source publications to confirm that the data accurately matches the official information. The data goes through several rounds of data validation to ensure data collection accuracy. After a successful validation stage, we perform further cleaning to the dataset to reduce any errors, inconsistencies and missing values in the official data. For example, we geolocate the organization’s unstructured addresses using the HERE REST APIs<sup>2</sup> to standardize 1,429 unstructured address values to 764 unique values. This improves the dataset by removing spelling errors and having locations in different languages. Since the source lacks consistent organization IDs, we also generate a unique organization identification number. For procurement authorities, we use the lowest available geolocation (district when available) along with a cleaned name to generate the identification number. For suppliers, we use the structured supplier city, cleaned name and a supplier’s legal form to tag organizations.

In the following analysis, we use 169,830 tenders which resulted in 267,427 contracts awarded between 2011 and 2022. Figure 1 shows the seasonality of public procurement purchases both in terms of the number of tenders and contracts (Panel A) and total spending (Panel B). Public procurement data became steadily available in 2011 and the publication rate increased in the following years, whereas total spending covered by the dataset fluctuates around 2.5 billion to 5 MKD per month with a slight increase in spending during the second half of 2021.

> 1 For a full description of the data standard see: https://opentender.eu/mk/about/how-opentender-works

> 2 - <u>https://developer.here.com/develop/rest apis</u>

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