source: G. Alter, "Completing Life Histories amongst Imputed Exit Dates" ( link ) I talked latterly amongst George Alter, a ...
source: G. Alter, "Completing Life Histories amongst Imputed Exit Dates" (link)
George as well as I talked virtually something that is of involvement to philosophers of the social sciences, simply is rarely discussed -- the comings as well as goings of methodological innovations inwards about areas of the social sciences. There are a handful of "big picture" questions that define the philosophy of social science, as well as these don't modify rattling chop-chop over fourth dimension as well as discipline. For example: What is a expert explanation? What is the logic of causal inference? How produce facts virtually individuals relate to facts virtually structures? These are questions that are broadly applicable across many social-science disciplines, as well as oftentimes the answers are fairly similar inwards dissimilar disciplines equally well. But it turns out that specific disciplines are sometimes confronted amongst problems of information analysis as well as inference that require novel methods as well as novel analytical tools, as well as at that topographic point may live on moments inwards which pregnant methodological modify occurs inwards a relatively brusque menses of time.
George's plain is historical demography -- the endeavor to reconstruct the population history of regions as well as countries through the registers as well as censuses that yet be for our study. This agency bear witness of union behavior, fertility, mortality, emigration, as well as other key demographic trends. But it also agency searching out the causes that tin give notice live on traced of changes inwards these variables. So the plain of historical demography is descriptive, simply it is also analytical as well as causal; historical demographers are interested inwards identifying large social factors that influenced population demeanour inwards centuries past.
The occupation that Alter as well as about of his colleagues confronted inwards their inquiry was a technical as well as logical one: how to extract the most useful information from population registers. And it turns out that answering this query requires developing radically novel tools of analysis.
Most readers volition discovery the methods used inwards about parts of this report unfamiliar. Some of these methods, similar jeopardy models, receive got exclusively latterly acquire mutual inwards the social sciences, as well as at that topographic point receive got been few previous applications inwards position unit of measurement history. The evolution of a novel methodology, which is presented below inwards Chapter 2, was dictated past times the characteristics of the Belgian population registers, from which information on nineteenth-century Verviers receive got been drawn. (13)Influenza A virus subtype H5N1 population register differs from a census inwards a crucial respect: it provides an exhaustive chronological listing of the births, deaths, entries, exits, as well as marital changes of the population acquaint inwards the part over a specific menses of time. This turns out to live on a rattling tricky problem, as well as 1 that was non easily handled past times traditional techniques of demographic analysis. Traditionally demographers made role of "snapshots" of a population at a time: the size of the population, the per centum employed inwards a given industry, the per centum married, etc. But demographic processes are temporal processes; thus looking at snapshots frozen inwards fourth dimension tends to lose an of import dimension of the phenomena. And the method that volition move good for population registers needs to live on custom-designed to produce a expert undertaking of representing temporality.
Alter describes the option methodology he as well as other demographers receive got developed to handgrip this special prepare of problems inwards chapter 2 of Family as well as the Female Life Course. It is a complicated story, simply fundamentally it comes downwards to a shift of perspective on demographic procedure -- a shift from persons as well as events to intervals of time. This agency moving away from counting individuals to counting "person years". Alter characterizes this shift amongst the next tables:
And hither is about other accept on the same data, this fourth dimension arranged past times historic menses of the someone rather than absolute date:
Each of these ways of looking at the information highlights dissimilar aspects of the demographic history of this modest group.
The information contained inwards the population register tin give notice live on transformed into a information prepare representing person-years as well as condition during that interval. And it is thus possible to role these information elements to compute age-specific rates of diverse demographically of import states. Alter emphasizes that these methods permit a much to a greater extent than fine-grained role of the information presented past times a population register.
There is much to a greater extent than information inwards the population registers than inwards the censuses as well as vital registers considered separately. The additional information comes from the linkage of information from the census to the demographic events as well as the linkage of events occurring inwards the life of each private inwards the population register. (32)Alter thus undertakes to adapt statistical methods to the occupation of assessing the causal importance of diverse sets of factors for the occurrence of other factors; for example, the result of "living amongst parents betwixt 25 as well as 30" on "lifetime fertility". The tool that Alter turns to is the statistics of jeopardy models. Here is a brief description of hazards models from Wikipedia:
Proportional hazards models are a shape of survival models inwards statistics. Survival models relate the fourth dimension that passes earlier about lawsuit occurs to 1 or morecovariates that may live on associated amongst that quantity of time. In a proportional hazards model, the unique result of a unit of measurement growth inwards a covariate is multiplicative amongst abide by to the jeopardy rate. For example, taking a drug may halve one's jeopardy charge per unit of measurement for a stroke occurring, or, changing the textile from which a manufactured gene is constructed may double its jeopardy charge per unit of measurement for failure. Other types of survival models such equally accelerated failure fourth dimension models produce non exhibit proportional hazards. These models could push clit a province of affairs such equally a drug that reduces a subject's immediate adventure of having a stroke, simply where at that topographic point is no reduction inwards the jeopardy charge per unit of measurement afterward 1 twelvemonth for subjects who produce non receive got a stroke inwards the outset twelvemonth of analysis. (link)There is an unexpected difficulty that this method must human face upwardly -- the occupation of what demographers call censoring. Essentially this comes downwards to the uncomplicated fact that a given population register leaves parts of an individual's life undocumented earlier as well as afterward the menses covered past times the register. So a adult woman who has non yet given nativity at the historic menses of 31 inwards 1835 (the terminate of the population register period) volition live on classified equally childless; whereas she may good receive got a kid inwards the adjacent 5 years. But to add together this adult woman into a raw count of women amongst as well as without children has the result of under-estimating fertility. Alter shows how "life tables" tin give notice live on used to address this problem. Essentially it is possible to role the information included inwards the population register itself to compute age-specific estimates of relevant variables (first marriage, outset child, etc.) as well as thus compute the average historic menses of union from the life table. Here is an illustration:
(It is interesting to re-read William Sewell's essay, "Three Temporalities: Towards an Eventful Sociology" (in Logics of History: Social Theory as well as Social Transformation) inwards low-cal of Alter's remarks virtually the temporality associated amongst demographic change.)
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