In 2017, the Republic of Georgia sent $272 million in exports to its neighbor, Azerbaijan. The same year, Azerbaijan reported receiving $74 million—that’s not a typo—in imports from Georgia. Goods worth $198 million seemingly disappeared before they reached Azerbaijani customs. The gap is a big deal. Azerbaijan taxes imports just above 5% on average (weighted for trade), which means its treasury missed out on collecting roughly $10 million in tariffs—0.1% of all government spending in that year—from just a single trading partner.

Many factors could explain the gap (see, for example, here, here, and here). Shippers might have rerouted goods to other destinations, the two countries’ customs offices might value goods differently, or the customs offices could have erred in reporting results or converting them to dollars. But one reason Azerbaijan’s reported imports are so low—not only here, but systemically across trade partners and years—is corruption and associated tariff evasion. Many traders likely undervalue and/or underreport their imports when going through Azerbaijani customs, and the sheer magnitude of the trade gap suggests the complicity or collusion of the authorities. The corruption involved might be petty (e.g., an importer bribing a customs officer to look the other way, or a customs officer pocketing the tax and leaving it off the books) or grand (e.g., a politician with a side business using her influence to shield imports from inspection; see here). A similar dynamic might also be at work in exporting countries: companies may undervalue exports to limit their income tax liability, possibly paying bribes to avoid audits.

Though Azerbaijan may be an extreme case, it is not unique. Economists have examined these export gaps (sometimes called “mirror statistics”) and have found similar discrepancies in, for example, Hong Kong’s exports to China, China’s exports to the United States, and Cambodia’s imports from all trading partners. Most recently, economists Derek Kellenberg and Arik Levinson compared trade data across almost all countries over an eleven-year time period, finding that “corruption plays an important role in the degree of misreports for both importers and exporters.” For lower-income countries, Professors Kellenberg and Levinson showed a positive relationship between a country’s level of perceived corruption, as measured by Transparency International’s Corruption Perceptions Index (CPI), and its underreporting of imports. The authors also showed a strong positive relationship between perceived corruption and the underreporting of exports across all countries.

Mirror statistics are an imperfect measure of customs corruption, to be sure, but they can serve two useful purposes in fighting this sort of corruption, and anticorruption reformers should pay more attention to this type of data. Continue reading →