their professional experience. The data are available for 2005–2014. We exclude countries with populations below 500,000, since they can be very different from the rest of the countries. Country-level data related to public procurement competitiveness are not available.

Measures of firm-level tax compliance costs are from the _World Bank Enterprise Surveys_ (WBES) conducted during 2006-2014.<sup>7</sup> We use four variables: whether the firm was visited or inspected by tax officials; the frequency of such visits; whether a gift or informal payment was expected or requested in any of the inspections or meetings with tax officials; and the extent to which tax administration is an obstacle to business operations. Firm-level procurement practices and costs are also taken from the WBES. The two variables of interest are: whether the firm has secured or attempted to secure a government contract over the last year; and whether the firm had to pay a bribe to get the contract. We restrict the sample of countries to those that are present in at least two survey waves.

Our main country-level controls comprise: GDP per capita, expressed in terms of purchasing power parity (PPP) from the _World Development Indicators_ (WDI) database and the overall polity score, from the _Polity IV_ database, which measures political competitiveness, executive recruitment, and constraints on executive action. To measure the level of development we use also gross secondary school enrollment; the number of Internet users from WDI; measures of the rule of law and government effectiveness from the _Worldwide Governance Indicators_ (WDI) database; and a measure of business freedom from the Heritage Foundation. In addition we use the time to enforce a contract, the time and number of procedures to start a business, and the time and number of procedures to register a property from DB database to construct a measure of the ease of doing business in a country.

Our firm-level controls are taken from the WBES and comprise firm productivity (real sales per employee) and a vector of indicator variables for whether a firm exports; is publicly traded; has foreign or state ownership; is of medium or large size; communicates with customers using e-mail or website; and has been in operation for less than five years.

Table 1 displays summary statistics of the main variables of interest. A full list of the variables with definitions is provided in Appendix A. Tables A.1–A.3 in the Online Appendix present additional statistics and correlations between the variables.

# **3. Empirical strategy**

To assess the impact of e-filing implementation at the country level, we employ a difference-indifference (DID) approach in a fixed effects estimation framework. The treatment is the year of e-filing implementation, which varies across countries. Countries that adopted e-filing systems during the sample period are the treated group, and countries that had implemented an e-filing system before 2005 or had not adopted a system by the end of the sample period are the control group. The inclusion in the

> 7 The _Enterprise Surveys_ are also known as the _Business Environment and Enterprise Performance Surveys_ (BEEPS) in the Europe and Central Asia (ECA) region.

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