25 28 John Harris and Michael Todaro, “Migration, Unemployment and Development: A Two-Sector Analysis,” American Economic Review 60:3 (1970): 126-142.

> 29 Timothy Krayenbuehl, Country Risk:  Assessment and Monitoring (Cambridge, MA:  WoodheadFaulkner, 1988); and Karemera, et al., “A Gravity Model Analysis.”

30Government stability is measured by ratings published on a monthly basis by the PRS Group in the <u>International Country Risk Guide. These ratings for “government stability” have a scale of zero to 12, with</u> zero representing those countries with “very unstable government” to 11 representing those with “very stable government.” For instance, in June 2000 the United States had a “government stability” rating of 11, while Poland had a rating of 6.

31The journal, International Investor, publishes annual ratings of countries’ credit ratings. These ratings have a scale of zero to 100, with zero representing those countries that are least credit worthy and 100 representing those that are most credit worthy. For example, in the year 2000 Switzerland had the highest country credit rating (93.8), while Afghanistan had the lowest (5.7).

32 See, for example, Karemera et al., “A Gravity Model Analysis,” p. 1750; Vogler and Rotte, “Effects of Development on Migration,” p. 502-503; and Hatton and Williamson, “What Fundamentals Drive World Migration?,” p. 11.

33 In a recent study of 50 developing countries using data from 1980 to present Adams found that income inequality (measured by the Gini coefficient) rises on average less than 1.0 percent per year. See Adams, Jr., Economic Growth, Inequality and Poverty, pp. 13, 20.

34 Identical results are obtained if the per capita GDP variable (and its square) are replaced by per capita survey mean income (and its square). The coefficient for survey mean income is positive and significant, and the coefficient for the squared term is negative and significant.

35 According to the World Bank, a country with a per capita GDP income of $1630 is classified as “lower middle income.” See World Bank, World Development Report 2000/01, p. 335.

36Vogler and Rotte, “Effects of Development on Migration,” p. 495; and Timothy Hatton and Jeffrey Williamson, The Age of Mass Migration: Causes and Economic Impact (New York: Oxford University Press, 1998), Chapter 3.

37 On this point, Hatton and Williamson observe that Sub-Saharan Africa has “generated remarkably few (international) migrants” to the major labor-receiving regions because the vast bulk of migration in Africa is within Africa and not abroad. See Hatton and Williamson, “What Fundamentals Drive World Migration?,” pp. 13-14.

38In the data set these two variables – log per capita GDP and log poverty headcount -- are highly correlated (-0.538), and so when they are both entered into the equations neither one of them is statistically significant.

39 Adams, Jr. provides some support for this hypothesis when he finds that the relationship between income and international migration in rural Egypt is an inverted U-shaped curve, with middle-income males having the highest propensity to migrate. See Adams, Jr., “Economic and Demographic Determinants of International Migration in Rural Egypt,” p. 164.

40 For similar findings, see Richard Adams, Jr., International Migration, Remittances and the Brain Drain: <u>A Study of 24 Labor-Exporting Countries, World Bank Policy Research Working Paper 3069, Washington,</u> DC, June 2003, pp. 11-16.