goods to the consignee’s warehouse once they have been cleared, blurring the specific role of ports and government border agencies in generating delays. Therefore, the fact that the coefficient on the LPI index never enters with a statistically significant sign contrary to the one on import uncertainty seems to suggest that the efficiency of Customs and other border agencies matters more than the performance of transportation companies. Second, to the best of our knowledge, this variable is the only available cross-country measure of uncertainty to date, and its statistical insignificance seems to imply that a more refined measure such as the one we use here may be necessary to fully grasp the implications of import uncertainty for export dynamics.

We also check whether our results are affected by the inclusion of proxies for access to finance. As mentioned in Section 2.1, liquidity-constrained firms are likely to face difficulties paying on time the duties and fees associated with the import process, thus leading to longer clearance times and higher uncertainty as measured by the interquartile range of the time to import. On the other hand, the micro-literature provides ample evidence of the detrimental impact of financial constraints on export dynamics.<sup>34</sup> If access to finance affects the ability of firms to enter export markets and survive while also influencing the time required to clear foreign inputs at the border, failing to properly control for its effect would yield biased estimates of the impact of import uncertainty on export dynamics. To address this concern, we consider two variables drawn from the WBES. To capture the burden imposed by loan requirements, we include the proportion of firms that had to provide collateral to obtain their most recent loan or line of credit. Alternatively, we use a broader indicator of the difficulties faced by firms to access the financing required to support their export activity, computed as the proportion of firms that needed a loan but did not apply for it owing to complex application procedures, unfavorable interest rates, excessively high collateral requirements, insufficient maturity and loan size, and anticipation of a negative decision by financial services providers. Results are displayed in Columns 11-20 of Table 9. Consistent with the literature, we find a detrimental impact of the proportion of loans requiring collateral on firm entry and first-year survival rates, with the coefficient on import uncertainty remaining unchanged across specifications. This is also broadly the case for the second variable capturing difficulties related to access to finance, which translate into depressed second- and third-year survival rates of entrants.

Furthermore, as described in Section 2.1, stages of the import process could be plagued by rent-seeking and corrupt practices, with Customs officials accepting informal payments for instance in exchange for modifying the classification or valuation of the imported good for tax purposes. Inspectors from other government entities such as SPS agencies involved in the clearance process could also engage in kickbacks and other illegal transactions that would ultimately influence the time required to clear foreign inputs at the border.<sup>35</sup> Accordingly, we check whether our results are immune to the inclusion of two indicators

> 34Using data for Chinese firms, Manova, Wei, and Zhang (2015) show that credit-constrained firms are less likely to penetrate foreign markets, in line with findings by Minetti and Zhu (2011) and Muˆuls (2015) for firms in Italy and Belgium respectively. Besides preventing firms from breaking into new markets, lack of access to finance also reduces export intensity (Bellone, Musso, Nesta, and Schiavo, 2010; Kiendrebeogo and Minea, 2016), and survival (Brenton, Cadot, and Pierola, 2012). For instance, Cadot, Iacovone, Pierola, and Rauch (2013) find that firms operating in a foreign market with limited presence of other firms from the same origin are less likely to obtain a credit from banks if they seek to ramp up production and exports, translating into lower survival in the foreign market.

> 35Based on the “efficient grease” theory, one could argue that an importing firm may find it rational to extend bribes so as to reduce the red-tape it faces at the border and speed-up clearance of its foreign inputs through Customs. In other words,

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