Voilà a most sensitive question, indeed, dear Mohammad. There a number of ways for defining the vulnerability of populations, such as health measurements, near-to-army-conflict civilians, high depgrees of debt in society, instability in social and ecoomic levels, and environmental perils (like near Volcanoe's population, flooding, etc.).

As it has always been in history, all in all, the most vulnerable population are the voiceless, the invisible, the untouchable - in one word: the poor and excluded.

I am very sincerely thankful to you Carlos. I do share and put your opinion in a very high esteem.

Thanks.

Dear Mohammad,

I posted a piece I wrote on poverty at the researchgate web where I surveyed and tried to graph some of the theories of poverty in economics. It includes Marx's explanation. I recall that A. Sen, the Nobel laureate in the area suggested that we should have policies to make them functional and capable. I should have included Gaitri Spivac's sociological and linguistic ideas about the sub-altern, which include the voiceless point that Carlos made.

Dear Lall Sir,

I will certainly go through your works, shortly.

If you have data on exogenous shocks (such as illnesses, natural disasters and so forth) and coping mechanisms for the poor (and maybe also for the non-poor), you can identify debilitating coping mechanisms such as selling off income generating/productive assets, holding off from important expenditures (such as cutting back on food, pulling children from school etc.) and/or borrowing as high interest rates. These options are typically consider as the last resort and the more vulnerable the population, the higher likelihood would be to resort to these.

In my opinion there is a more important aspect that you have to consider that is the mobility of the society. But we have official data about this phenomenon, so you have to analyze microdata 

 Population vulnerability could be defined in terms of the kind of risk due to an exogenous perturbation. For example, poor people are vulnerable to undesirable effects derived from climate change on their welfare

Provision of services to households is in an indicator, Power, water supply, transportation, energy for cooking, etc. the price paid or share of income used, as well as whether these services are there at all,

Mohammad, In my work around affordable housing in the US, it is common to equate vulnerablility to the amount of household income spent on housing. Once an individual or family cannot afford a place to live and they become homeless, all sorts of negative follow-on events tend to occur driven by health and nutrition issues, not to mention employment, socialization, and education challenges. Accordingly, the benchmark for approrpiate expenditure on housing is considered to 30% of gross income and once that amount surpasses 50%, the family is considered to be vulnerable to further negative consequences to follow.

However, I know that in too many parts of the world, what we define as "vulnerable" and the living conditions that represents would be considered a high standard of living and vulnerability is based on even more critical and dire outcomes related to life expectancy, infant mortality, and perhaps exposure to war and terror.

Perspective is everything. Peace.

Based on appropriately diversified local participation (context oriented) you should be able to define how they understand a not vulnerable population; the minimum required for not being a vulnerable location (a hypothetical construct). You can convert this understanding into a list of variables ranked by their importance (always context oriented). Then you can compare the distance of any location, in terms of those variables, to the not vulnerable one. This way you can find which locations are vulnerable, their degree of vulnerability and by which variables exactly.

vulnerable could be those that could be easily exploited...the women,adolescents,the tribals, the old, the transgenders  and the like

Dear all

I add that the method of classification depends on considering the monetary or non monetary aspect of vulnerability. The monetary vulnerability is defined generally by considering the population belonging the second quarter of the population, while the vulnerable population in the non monetary sense is generally classified according to some selected characteristics.

The United Nations defines (macro) economic vulnerability as the risk for a country of seeing its development process hindered by exogenous external shocks. This definition has micro foundation since many households in developing countries may fall in a poverty trap, or be caught in a poverty trap, when facing unforeseen events such as climatic shocks, international commidity price shocks etc. Vulnerable countries/households are characterized by a high exposure to large and frequent shocks (caused by a lack of diversification of economic activities for instance) and a low resilience to them (caused by a lack of access to formal and informal fiancial services, pro-cyclical public policies, etc.)

Pupulation vulnerability can be definined by mean a income indicator:

Income less food basket cost

Income under Poverty line or welfare line

but considering another minimun indicator such as: scholarship year; health attention, house quality materials walls, roof an floor

house services: water in door, electricity

Vulnerability can be defined and demarcated from various points of or through a combination : 

poverty point of view based on income/welfare/hhappiness 

Gender point of vviewable point of view especially focussed on children and girl cchildren rural development point of view or infrastructural point of view particularly centred on backward communities & remote dwellers

Disability point of view

Vulnerability, in the economic sense, could also mean being at or below the poverty line i.e. living on less than 1.5 USD per day. This implies that vulnerable groups are unable to meet  the basic needs in sufficient quantities, including food, shelter, clothing, health and education.

Vulnerability can be defined in terms of limited degrees of freedom. The freedom that avenues and opportunities afford is a function of creativity and political will. These are the two that ultimately lock economies into a doom loop if they are lacking. Constraints to adaptive/learning capabilities is at the crux of vulnerability in poorer segments of the economy, or poorer economies as a whole.

Just came upon this question.... a little late - like by 5 years. Mohammad Israr Khan how did you resolve this question? To add to this discussion, I would love to see 'vulnerable' and 'vulnerable population' be stricken from research and policy work and discussions as it is highly problematic, on a number of fronts, and is very telling of the writer/researcher's (social, geographic, political, economic) positioning. In public health (the relm I dwell in) and many other spaces (like your area of focus), me (someone who is gay, Two-Spirit and Indigenous) and my community are often described as 'vulnerable'. How is it that my sexuality and/or my Indigeneity makes me vulnerable? Rather, it is the systems of: homo, trans and bi -phobia, settler colonialism and hetrosexism (to list a few) that makes me more susceptible to poorer health (and other) outcomes. "Vulnerable" diverts the focus and/or gaze on me, the individual, and/or a population. Implicitly, often there is the impression that must be something wrong with me or my community that makes me vulnerable. In my case, who I am and who I sleep with. While we need to focus on either dismantling or challenging the systems that are causing the harm. Then and only then we will have real changes in the various system(s) of oppression and all the (social, geographic, political, economic) privileged people will have to look inward to see how they are actively or passively supporting and are benefiting for those systems. For if there was real change (equity), these very people would have to give up their (social, geographic, political, economic) privilege (share power) and come to the understanding that are no more special than anyone else! I hope you understand; I'd be happy to discuss this with you in greater detail - [email protected].