Category Archives: Development

Exports & HIV in Africa

Emily Oster finds a downside to exports in Africa – transportation and trade spread epidemics (pdf):

I find a large and significant positive relationship between HIV and exports: a doubling of exports appears to lead to as much as a quadrupling in number of new HIV infections, which suggests that if exports overall had been 25% lower in Africa over the course of the epidemic only about half as many people would have become infected. In addition, this relationship seems to explain at least some of the very large decline in HIV prevalence in Uganda in the 1990s, which is typically attributed to the ABC (Abstain, Be Faithful and use Condoms) campaign, a widely replicated anti-HIV education effort. A decline in the coffee market accounts for between 30% and 60% of the decline in HIV incidence, suggesting the success of the ABC campaign may be overstated…

A central concern with interpretation is the possibility that is not the export-transit mechanism which drives the result but, rather, some omitted variable (for example, GDP) which drives both exports and HIV. Although this is potentially consistent with the primary results, I argue that there is evidence in favor of a causal interpretation of exports. First, the relationship between HIV and exports is stronger in areas with a greater density of roads and areas closer to ma jor cities, which is consistent with the transit mechanism. Second, instrumenting for export volume with world commodity prices also points to a positive and significant relationship. Third, the relationship between exports and HIV is stronger in countries where the major export is more closely linked to trucking. Finally, new HIV infections can be linked directly to truck imports, which strongly points to an effect of transit.

Of course, it’s not international trade per se that increases the spread of HIV. If economic activity within national borders spurred increased use of truckers to transport goods, that would result in the same effect. And the benefits of economic growth may outweigh the costs of higher HIV incidence. Nonetheless, this isn’t good news.

[HT: MR]

Why economists need epidemiologists

Tim Harford says that Emily Oster’s work on AIDS has serious flaws:

One of her celebrated articles is an analysis of the Aids epidemic in Africa: she offers her own epidemiological model and concludes that the virus is best fought by treating other sexually transmitted diseases. The research was published in the prestigious Quarterly Journal of Economics (QJE) in May 2005.

But Oster’s conclusion is probably wrong. Epidemiologists embraced the idea of treating other sexually transmitted diseases a long time ago, but it has been discredited (to their deep disappointment) by a series of rigorous clinical trials. Oster says that the most convincing evidence came out after her paper was written; still, she has repeated her recommendations more recently in Esquire magazine.

Oster also made a mistake in handling her data. The error – which she has acknowledged, and which makes a modest but noticeable difference to her calculations – was quickly spotted when I asked two epidemiologists to review her research. The QJE will be publishing a correction.

Oster quite reasonably says that her article has other merits. But it might have been much better if the epidemiologists had taken a look long before the FT got involved.

The problem is that the economists couldn’t get the epidemiologists to take the research seriously enough to comment. Oster tells me that she tried, but she couldn’t name an epidemiologist who was familiar with her QJE paper. And Larry Katz, the QJE editor who published Oster’s paper, acknowledges that the epidemiologists would not typically agree to review papers for the QJE.

Props to Harford for his productive contributions to the research process.

“Cultural assimilation, cultural diffusion and the origin of the wealth of nations”

Quamrul Ashraf & Oded Galor propose a cultural explanation for economic growth, but it’s not the usual story:

A thousand years ago, Asia was ahead. Why is Europe richer now? Asia was geographically less vulnerable to cultural diffusion and thus benefited from enhanced assimilation, lower cultural diversity and greater accumulation of society-specific human capital; this was an edge in the agricultural stage. Greater cultural rigidity, however, diminished the ability to adapt to a new technological paradigm, delaying their industrialisation.

Full Vox column.

"Cultural assimilation, cultural diffusion and the origin of the wealth of nations"

Quamrul Ashraf & Oded Galor propose a cultural explanation for economic growth, but it’s not the usual story:

A thousand years ago, Asia was ahead. Why is Europe richer now? Asia was geographically less vulnerable to cultural diffusion and thus benefited from enhanced assimilation, lower cultural diversity and greater accumulation of society-specific human capital; this was an edge in the agricultural stage. Greater cultural rigidity, however, diminished the ability to adapt to a new technological paradigm, delaying their industrialisation.

Full Vox column.

Trade and inequality — in developing countries

From the NBER Digest:

While trade liberalization was expected to help the less skilled, who are presumed to be the relatively abundant factor in developing countries, there is overwhelming evidence that they are generally not made better off relative to workers with higher skill or education levels.

One of the few uncontroversial insights of trade theory is that changes in a country’s exposure to international trade, and to world markets more generally, affect the distribution of incomes within the country. Not surprisingly, the entry of many developing countries into the world market in the last three decades coincides with changes in various measures of inequality in these countries. What is more surprising is that the distributional changes went in the opposite direction from what the conventional wisdom suggests: while trade liberalization was expected to help the less skilled, who are presumed to be the relatively abundant factor in developing countries, there is overwhelming evidence that they are generally not made better off relative to workers with higher skill or education levels.

In Distributional Effects of Globalization in Developing Countries (NBER Working Paper No. 12885), authors Pinelopi Koujianou Goldberg and Nina Pavcnik attempt to explain this paradox. They question whether the underlying conventional wisdom is too stylized to capture the reality of the developing world and they ask whether other forces at work may have overridden the effects of globalization. They also examine the mechanisms through which globalization has affected inequality and try to determine whether general lessons can be drawn from the experience of the last three decades.

The authors’ findings suggest a contemporaneous increase in various measures of globalization and inequality in most developing countries, although establishing a causal link between these two trends has proven more challenging. However, the evidence has provided little support for the conventional wisdom that trade openness in developing countries would favor the less fortunate.

The authors also find little support for the premise that adjustment to changing economic conditions would occur through labor reallocation from declining to growing sectors of the economy, at least at the aggregate industry level usually considered in traditional international trade models of comparative advantage. A common finding of studies of the effects of trade reforms in developing countries is the lack (or small magnitude) of sectoral labor reallocation. In some instances, the data also suggest that the wage response to trade barrier reductions is more pronounced than the employment response.

The cumulative evidence points to constrained labor mobility as one plausible explanation for the lack of sectoral reallocation. Indeed, the strict labor market regulation that many developing countries had in place prior to the recent reforms is a potential source of labor market rigidities. The importance of these rigidities is likely to diminish in the long run, especially since many developing countries have by now significantly liberalized their labor markets.

The authors’ findings highlight several globalization-based explanations for the increased relative demand for more educated workers within industries. In some cases, trade reforms that liberalized, in addition to goods flows, factor flows (most importantly capital) may have generated additional demand for skilled workers. In other instances, globalization affected not only trade in final goods, but also trade in intermediate goods that, from the developing country perspective, were skill-intensive. Even in those cases where liberalization was concentrated on final goods, the highest trade barrier reductions often were concentrated – contrary to conventional wisdom – on low-skill sectors that originally had enjoyed a higher level of protection. Technological change that favored skilled workers may have interacted with trade reforms to further depress the relative demand for low-skilled workers. Increased exposure to currency fluctuations boosted exports from developing count! ries in some cases and provided incentives to upgrade the product-mix of their domestic plants. These compositional changes may have fostered a quality upgrading of plants that further contributed to the widening of the wage gap between skilled and unskilled.

Overall, it appears that the particular mechanisms through which globalization affected inequality are country-, time- and case-specific; that the effects of trade liberalization need to be examined in conjunction with other concurrent policy reforms; and that implementation details of particular policies matter. This conclusion may seem disappointing, according to the authors, as it offers no simple predictions regarding the distributional impact of globalization and hence no straightforward recipe for remedial measures to alleviate potentially adverse impacts. Yet, it is hardly surprising given the heterogeneity of countries, reforms, and overall globalization experience within the developing world.

Finally, the authors emphasize that most of the existing evidence refers to narrow measures of inequality such as the skill premium, or wage inequality. Broader concepts of inequality that focus on consumption and general well-being have received substantially less attention. The very scant evidence that exists on these issues, however, seems to suggest that the labor market effects of globalization dominate its effects on consumption through relative price changes, so perhaps the focus on wages alone is not as limiting as one would have thought.

NBER working paper 12885.

Chinese cloning

Here’s a great Popular Science article on China’s industrial development via copying developed country manufacturers. I’m not terribly concerned about the patent violations slowing innovation, but the trademark issues are troubling from a consumer perspective in terms of knowing who actually made the good you’re purchasing.

[Hat tip: Patri.]

China’s product quality

Via David Altig, a WSJ piece that’s skeptical of China’s ability to ascend the product quality ladder:

China’s industries are composed of hundreds of thousands of tiny factories and farms — plus traders, brokers, haulers and agents, all of whom take control of the goods and materials but add little value to the product. With every additional player in the chain, the cost, risk and time grow. Effective quality control in this environment is difficult… As the product recalls demonstrate, China can barely make low-value goods reliably, much less higher-value ones. The problems are structural, not the result of a few bad apples…

To compete head-to-head with the American economy, China will have to revolutionize the very way its industries are organized. It must shake out the thousands of low-value middlemen and integrate the tiny factories into larger, more competitive companies. It must train a workforce in modern technology and business practices. And, it must instill transparency and a uniform rule of law. Such an effort could span generations.

These observations complement more scholarly work in weakening Dani Rodrik’s argument that China’s export profile is unusually sophisticated.

China's product quality

Via David Altig, a WSJ piece that’s skeptical of China’s ability to ascend the product quality ladder:

China’s industries are composed of hundreds of thousands of tiny factories and farms — plus traders, brokers, haulers and agents, all of whom take control of the goods and materials but add little value to the product. With every additional player in the chain, the cost, risk and time grow. Effective quality control in this environment is difficult… As the product recalls demonstrate, China can barely make low-value goods reliably, much less higher-value ones. The problems are structural, not the result of a few bad apples…

To compete head-to-head with the American economy, China will have to revolutionize the very way its industries are organized. It must shake out the thousands of low-value middlemen and integrate the tiny factories into larger, more competitive companies. It must train a workforce in modern technology and business practices. And, it must instill transparency and a uniform rule of law. Such an effort could span generations.

These observations complement more scholarly work in weakening Dani Rodrik’s argument that China’s export profile is unusually sophisticated.