Toward a Disability Development Index

An idea in the rough, by Paul Bohman. First draft 13 October 2007. Last updated 26 December 2007.

Summary: I propose an new index in the context of international development—a Disability Development Index (DDI)—to supplement the Human Development Index (HDI) and other official indexes in the annual Human Development Report published by the United Nations Development Programme. Because people with disabilities have functional limitations requiring accommodations and an economic safety net, the well-being of people with disabilities is an effective barometer of a society's commitment to the well-being of all its members. A Disability Development Index would take into account the unique situation of people with disabilities, such as the need for assistive technologies and accessible infrastructure in both physical and virtual environments. It also takes into account the additional costs associated with living with a disability. Standard measures of poverty underestimate the poverty experienced by people with disabilities. A Disability Development Index would shed new light on the inequalities and deprivations that people with disabilities have always experienced, allowing the opportunity to focus efforts on ameliorating them to the extent possible.

1. Human Development

The United Nations publishes its Human Development Reports (HDR) every year, with indicators of national well-being that extend beyond simple economic measures such as Gross National Product (GDP), Gross National Income (GNI), or other purely financial measures. The most prominent measure in the HDR is the Human Development Index (HDI), which includes measures related to 1) a long and healthy life (measured by life expectancy), 2) knowledge (measured by the adult literacy index, gross enrolment index across primary, secondary, and tertiary education), and 3) a decent standard of living (measured by GDP and purchasing power parity [PPP]). The HDI is far from comprehensive in measuring human well-being, but it at least moves the conversation in the right direction.

Recognizing the value of more targeted indices, the Human Development Report includes additional reports: The Human Poverty Index for developing countries (HPI-1), the Human Poverty Index for selected OECD countries (HPI-2), the Gender-related Development Index (GDI), the Gender Empowerment Measure (GEM), and the Technology Achievement Index (TAI). Each of these contributes basic information about these specific aspects of human development.

Countless other focus areas would shed additional light on human development. High on the list of possibilities are:

  • Human Rights Index
  • Democratic Empowerment Index
  • Environmental Sustainability Index

A Human Rights Index could be further subdivided to account for specific human rights such as freedom of expression, freedom of conscience/religion, and so on. The data could also be disaggregated according to specific demographic characteristics, such as race, gender (the GDI and GEM already do this to a large extent), religion, ethnic heritage, geographical region, income, sexual orientation, and disability status. Each of these reports would be valuable. I would like to focus here on the last criterion: disability status.

The well-being of people with disabilities is an effective barometer for the depth and breadth of poverty reduction strategies and the level of commitment to human rights issues. Disability, especially in developing countries, is associated with poverty in a vicious cycle in which the presence of one increases the likelihood of the other. Poverty puts people at risk for disabilities. Disabilities put people at risk for poverty. The literature on disability frequently states that people with disabilities are among "the poorest of the poor." They experience difficulties finding and obtaining employment, converting income into well-being, participating in political processes, engaging in community events, receiving an education, and, on the most basic level, being able to enter buildings or use public toilets. The disabilities themselves are burdensome. The barriers created by societal constructions—in both the figurative and literal sense—increase the burden, and create additional unnecessary disabilities.

2. What Would a Disability Development Index (DDI) Measure?

Many things could be included in a Disability Development Index (DDI), including all of the issues mentioned above. For the sake of consistency, though, it would probably make the most sense to include indicators similar to the Gender-related Development Index. As with the HDI, the GDI measures 1) a long and healthy life, 2) knowledge, and 3) a decent standard of living. The difference is that the GDI compares the measures between men and women. A DDI would do the same thing, with the focus on disability rather than gender.

2.1. A Long and Healthy Life

Life expectancy of people with disabilities. A long life is not necessarily the same thing as a healthy life, but considering the complexity in measuring health vs. the ease of measuring life expectancy, it is no wonder that life expectancy is used as a proxy for both. A DDI could likewise use life expectancy of people with disabilities to approximate measures of a long and healthy life. The data for people with disabilities in this category will always be lower than for the population as a whole. Achieving exact parity between people with and without disabilities is impossible, considering the nature of some types of disabilities. Still, the smaller the gap, the healthier the society.

Disability prevalence 0-40 yrs. Disabilities are a normal part of the human condition and are not eradicable in the same sense that smallpox is eradicable, but high rates of disabilities among young populations can be evidence of other problems such as violence, malnutrition, poverty, or the unavailability of medical services. Disabilities among older populations can actually be evidence of the reverse set of conditions: populations with a longer life expectancy are more likely to show an increase in age-related disabilities. With this in mind, it makes sense to include only a younger population in the data analysis here.

2.2. Knowledge

In many developing countries, people with disabilities are excluded from educational opportunities for a variety of reasons, including inaccessible classrooms and restroom facilities, teachers without the expertise to integrate students with disabilities into their classrooms, and prejudice against—or superstition about—people with disabilities. A lack of educational opportunities translates into a lack of economic opportunities and a life of dependence and disempowerment.

Enrolment rates of people with disabilities. Enrolment in primary, secondary, and tertiary education programs—as with the HDI—is an acceptable measure of knowledge for people with disabilities. It is important to note that some types of disabilities, such as profound cognitive disabilities, make enrolment in mainstream educational programs unfeasible for some, so an overall enrolment of 100% is impossible.

2.3. A Decent Standard of Living

In the HDI, a decent standard of living is indicated by GDP, which is not very meaningful in this context. In the HPI-1, a decent standard of living is indicated by 1) the percentage of the population not using improved water sources, and 2) the percentage of children under five who are underweight. In the HPI-2, a decent standard of living is indicated by the percentage of people living below the poverty line. Data along any of these lines would be valuable.

In the context of disabilities, I propose including three broad categories of information:

  1. Family income, adjusted for disability costs
  2. Ownership of (or reliable access to) consumer assistive technologies
  3. Accessibility of the physical and technological infrastructure

2.3.1. Family Income, Adjusted for Disability Costs

Why family income? Disability is often a family phenomenon. The poverty rate for families with at least one person with a disability is higher than for the families in which no one has a disability. The family often bears the extra costs associated with the disability. Family members may contribute directly to caring for the family member with a disability, or may pay collectively for necessary services. Recognizing the centrality of the family unit in absorbing disability costs helps give a more accurate perspective on the cost of disabilities.

Why adjust for disability costs? Income is important to everyone. It is especially important to people with disabilities. Living with a disability almost invariably costs more than living without a disability. Unfortunately, people with disabilities experience high unemployment and under-employment rates, even accounting for those whose disabilities preclude working. Many who do work find themselves in low-skill, low-paying jobs. The low pay combined with the cost of the disability can reduce their effective income substantially, depending on the type of disability. The ability to convert income into well-being can be significantly lower than for the general population. The technicalities of how to adjust for disability status can prove problematic, but there is precedent. Kuklys (2005) pioneered a method of adjusting for disability costs in the calculation of income and poverty among people with disabilities in the UK.

2.3.2. Ownership of (or Reliable Access to) Consumer Assistive Technologies

To a person who cannot walk, a wheelchair can offer a degree of freedom and independence possible through no other way. A person who is blind can experience a similar degree of freedom with the addition of a cane or a guide dog. A person with a communicative disorder may be able to communicate only through the use of an augmented or alternative communication (AAC) device. A blind person cannot access a computer without a screen reader. Each of these assistive technologies can make a big difference in the life of a person with a disability. The impact and relative importance of a given assistive technology device is context-dependent. Screen readers are very important to people who are blind in industrialized nations. In nations where computer access is rare for anyone, having a screen reader is lower on the list of priorities. Data collection and reporting efforts will need to take into account these differences (see also section 3 of this post below). The index would also need to standardize a list of functional disabilities and their associated assistive technologies. For example, a person without the use of the legs could be expected to need a wheelchair.

2.3.3. Accessibility of the Physical and Technological Infrastructure

The physical infrastructure can include both public entities and privately-owned entities. Among the public entities are public transportation systems, roads and sidewalks, government buildings, schools and universities, libraries, hospitals, parks, etc. Among relevant privately-owned entities are restaurants, grocery stores, market places and retail stores, sports arenas, offices of private practice professionals, etc. The list of disability accommodations in the physical environment can be quite lengthy. To ease data collection, the list could be limited to a few key elements such as:

  1. Wheelchair access to buildings (which could include one or more of the criteria: ramps, elevators, toilets, width of doors and hallways, parking spaces, automated doors, etc.)
  2. Blind access to buildings (e.g. Braille door numbers and signs)
  3. Wheelchair access to streets and intersections (e.g. sidewalks, curb cuts)
  4. Blind access to streets and intersections (e.g. tactile floor tiles to indicate caution, for example at an intersection; audible cross walk signals)

Reporting this data would require a standardized data collection instrument for rating the accessibility of the physical infrastructure. To my knowledge, no such instrument exists, but an instrument could be created based on disability rights laws in countries that have them, such as the Americans with Disabilities Act in the United States, and the Disability Discrimination Act in the UK. The scope of the data collection would need to be limited, and it may prove expedient to examine only public entities to simplify the data collection process.

The technological infrastructure includes the internet, television, automated teller machines, telephones and fax machines, copiers, etc. It would be unfeasible and unnecessary to examine all internet sites, telephones, or other such ubiquitous technologies, but a selected review of certain technologies would be helpful. Data collection could be limited to key indicators such as:

  1. The accessibility of publicly-funded internet sites (e.g. federal and regional government sites) according to international standards such as the Web Content Accessibility Guidelines
  2. The presence of captions on broadcast television shows

Note: In the poorest or most technologically-deprived countries, measuring the accessibility of the technological infrastructure would mean little in relation to the scarcity of technology overall. This category is most relevant to technologically-advanced societies.

3. Different Indices for Technology-Poor vs. Technology-Rich Countries?

It may make sense to implement two indices: one for countries with limited technological resources and another for nations with an abundance of advanced technologies. They could be called DDI-1 and DDI-2, respectively, to mirror the nomenclature for the Human Poverty Indices (HPI-1 and HPI-2). These could be defined as follows:

DDI-1: Disability Development Index 1 (for technology-poor countries)

  • A long and healthy life
    • Life expectancy of people with disabilities
    • Prevalence of disabilities among people age 0-40 years
  • Knowledge
    • Adult literacy rate of people with disabilities
    • Gross enrolment ratio (GER) of people with disabilities
  • Decent standard of living
    • Adjusted Family Income: Family income of families with a disabled person, adjusted for disability costs
    • Assistive technologies: Wheelchair ownership among people who need them
    • Infrastructure: Wheelchair accessibility of public buildings (ability to enter building [e.g. ramps], ability to use building [e.g. elevators, doors, halls, toilets]

Note: The above index does not take into account the accessibility needs of non-motor disabilities, such as blindness, deafness, or cognitive disabilities. Measuring the accessibility of the infrastructure to these disabilities is more difficult in technology-poor countries.

DDI-2: Disability Development Index 2 (for technology-rich countries)

  • A long and healthy life
    • Life expectancy of people with disabilities
    • Prevalence of disabilities among people age 0-40 years
  • Knowledge
    • Adult literacy rate of people with disabilities
    • Gross enrolment ratio (GER) of people with disabilities
  • Decent standard of living
    • Adjusted Family Income:
      • Family income of families with a disabled person, adjusted for disability costs
    • Assistive technologies:
      • Wheelchair ownership among people who need them (inability to use legs)
      • Screen reader ownership among people who need them (blind)
    • Infrastructure:
      • Public buildings:
        • Wheelchairs (ability to enter building [e.g. ramps], ability to use building [e.g. elevators, doors, halls, toilets]
        • Blindness (Braille on elevators, room signs, etc.)
      • Transportation and roads
        • Wheelchairs (public transportation vehicles and stations, sidewalks and intersections)
        • Blindness (audible crosswalk signals, warning tiles at intersections)
      • Television broadcasts:
        • Captions
      • Publically-funded internet sites
        • Conformance to Web Content Accessibility Guidelines (e.g. at Level 2)

Note: The above index does not include measures explicitly for people with cognitive disabilities.

4. The Data Problem

The biggest problem with the proposed Disability Development Index is the lack of data from which to derive an index. Data do not exist for many countries, especially in the developing world. Where data do exist, it is often impossible to compare data between countries or data sets, due to methodological differences in definitions and data collection strategies. Until more reliable data exist, the Disability Development Index is not practical. This is not a statement of defeat, however, so much as a call to collect data and define it more consistently across data sets.

5. Why Disabilities Deserve to be Indexed Separately

People with disabilities experience functional limitations due to their biology, but they also face disabling circumstances in the built environment, virtual environments, and societies in which they live. No other category of people is more in need of an economic safety net than people with disabilities, due to the difficulties faced (from various causes) in achieving an adequate income and in converting that income to well-being (due to the added cost of the disability). People with disabilities have specific needs in terms of assistive technologies and infrastructure which, when met, substantially increase independence and overall well-being. Less specific measures of overall poverty, life expectancy, and income fail to capture these important differences. Only a separate index can bring disabilities to the forefront where they can be examined and addressed effectively.

References

Kuklys, W. (2005). Amartya Sen's Capability Approach: Theoretical Insights and Empirical Applications. New York: Springer.