In many parts of the developing world, notably in India and China, the ratio of women to men is suspiciously low. In developed countries, males outnumber females at birth, but that imbalance begins to redress itself soon after. The combined effect is (or should be) a roughly equal proportion of men and women in the population as a whole. That is not the case in large parts of Asia: in India and China, the overall ratio of males to females is around 1.06.
It is fair to say that the literature on missing females places a decided emphasis on female discrimination in the pre-natal and infant/early childhood stages. For instance, Monica Das Gupta (2005) summarizes the literature by stating that ""the evidence indicates that parental preferences overwhelmingly shape the female deficit in South and East Asia"". Several researchers have emphasized the skewed sex ratio at birth, which could indicate sex-selective abortion. Others have focused on early childhood and the possibility that young girls are systematically less cared for.
In contrast, recent research by Siwan Anderson and Debraj Ray (2010) implies that missing women are spread far more widely over age and disease. While the authors do not dispute the existence of severe gender bias at young ages, they introduce a methodological procedure to ""decompose"" the overall number of missing women into various age-disease categories. Two striking conclusions of relevance to our project are: (1) The majority of missing women in India and sub-Saharan Africa and a significant proportion of those in China are of adult age; and (2) Almost all the missing women stem from disease-by-disease comparisons and not from the changing composition of disease, as described by the epidemiological transition. Yet Anderson and Ray stress that their approach is only suggestive of different pathways of gender bias: ""Much more work is needed to identify the underlying mechanisms."" Are women relatively prone to illness, do they seek medical care less often, conditional on being ill, or do they receive poorer care, conditional on seeking care?
Both the focus on adult excess female mortality as well the pathways are of fundamental importance. If half or close to half of the active labor force is under a skewed threat to their health, the attendant implications for economic productivity have a direct relevance for economic growth (quite apart from the intrinsic injustice of that skewness). Our research studies eye care, but not because we feel that vision is the most important of all health-related outcomes. Rather, eye care is a highly tractable component of health from the research viewpoint: different aspects of eye disease, such as myopia, cataract or glaucoma, are easily measurable. Using various measures of disease intensity, we will evaluate the extent to which eye health deteriorates before men and women seek care. That is, we begin by studying waiting times to first treatment. Second, we propose to document gender differences in the probability of follow-up visits conditional on similar levels of health at the first stage of evaluation. Third, we seek to understand the underlying reasons for the observed health differences across gender.