to health spending, but not to health. Third, the technical efficacy of some health care spending (on garlic as a cure for AIDS, for example) is very low or even zero, so that even if some publicly financed services are delivered to patients, they might have little effect.

One way to examine the impact of public spending on health is to employ cross-country regression techniques, as in the health-income literature reviewed above. In this case, though, we can be somewhat more confident about the use of cross-country comparisons, because problems of endogeneity seem to be less severe: it is unlikely that better population health would, in itself, lead to greater public spending on health.

Filmer and Pritchett (1999) regress under-five mortality on a variety of variables, including public health spending, and find that virtually all the cross-country variation is attributable to average per capita income, its distribution, female education, ethnolinguistic diversity, and religious and regional dummy variables. That is, health spending is more or less uncorrelated with health outcomes: independent variation in public health spending explains a paltry oneseventh of 1 percent of the variation in child mortality.

Wagstaff and Claeson (2004) examine how these results are affected by good governance. They find that health spending does reduce under-five mortality as long as the quality of governance, as measured by the CPIA (country program and institutional analysis) index, is high.<sup>10</sup> Flawed institutions would be expected to produce limited and poor-quality health services. But Lewis (2006) finds no association between the effectiveness of health spending and proxy measures for the effectiveness of institutions in the health sector—either the government effectiveness or the corruption measures of Kaufmann, Kraay, and Mastruzzi (2005).

One channel through which public spending may affect health—and one that, implicitly or otherwise, motivates some calls for greater spending—is its impact on the poor. Bidani and Ravallion (1997) find that public health spending significantly affects the health of the poor, but (consistent with Filmer and Pritchett 1999) not aggregate health.

In more recent work, Boone and Zhan (2006) investigate the determinants of child mortality using survey data on 278,000 children in 45 low-income countries. Their results provide some nuances to those of Filmer, Hammer, and Pritchett (2000). Somewhat controversially, they find that the prevalence of common diseases and the supply of infrastructure such as water and sanitation are _not_ good predictors of child mortality, but that parents’ education and a mother’s propensity to seek out modern medical care are. Here the simulated effects they report appear large: for example, they find that if all mothers and fathers in the 45 countries had years of schooling equal to those of parents in Egypt, child mortality in these countries would fall by 19 percent. They also report that halving the prevalence of diarrhea, fever, and cough would reduce child mortality by only 3 percent.<sup>11</sup>

> 10. This is good news as much for health spending as for the CPIA index as a measure of governance. “Good” public spending should lead to improved health outcomes (unless it simply crowds out private spending), so the fact that countries with high CPIA scores show a positive link from spending to health is consistent with the CPIA measuring something relevant.

> 11. These numbers are, however, difficult to apply to decision making, as the costs of the two hypothetical interventions are not reported.

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