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  • #PAA2016 where to find me

    Here is my PAA 2016 program entry:

    You can also find me on Wednesday, March 30 at the HMD side meeting in the morning, and at the dataviz workshop in the afternoon. I intend to sleep at night. Most paper submissions currently on the website will be updated before March 7 too.
    Posted Feb 5, 2016, 6:53 AM by Tim Riffe
  • dataviz workshop pre #PAA2016 @PRBdata @minnpop @MPIDRnews
    The following annoucement went out in the most recent issue of PAA Affairs:

    PAA Data Visualization Workshop 2016: PAA attendees with an interest in data visualization are invited to attend a pre-PAA workshop to be held on Wednesday, March 30, 2:00-6:00 pm at the Population Reference Bureau office in Washington DC (close to the PAA venue and located at 1875 Connecticut Ave NW, Suite 520). This workshop will include a mixture of short presentations and lots of hands-on exercises with a special focus on visualizing demographic data (stocks, flows, intensities, etc.) in commonly used communication media, such as articles and presentations. All levels of experience are welcome. There is no participation fee, but space is limited. If you are interested in participating and/or would like to be on our listserv, please send an email to Audrey Dorélien and Tim Riffe at paadataviz2016@gmail.com. This workshop is supported by the Max Planck Institute for Demographic Research, the Minnesota Population Center, and the Population Reference Bureau.

    Here's a flyer that Erica Nybro put together (graphic from yours truly)

    More program details are available below. I think that all levels of dataviz saaviness could benefit from this workshop, and it's a short walk from the Marriot to PRB (or 1 subway stop): 

    Also, if you bring your PAA presentation, there's a good chance we can arrange from group critique of it's visual characteristics. Likewise for yet-to-be-printed posters, but in that case, you'd need to arrange for quick printing yourself, which might cost more than your other options. Also, it'd be best to let us know well in advance (via that special email address!, not our personal ones), so we can have a chance to work it in. The venue probably holds 35-40 people. Organizers and host participants might end up being 6-8 of those, so space is limited. If you're interested, please email 
    paadataviz2016 (at) gmail.com

    Here's a preliminary agenda:

    I Overview (45 min) Audrey DorelienJon Schwabish, and Jonas Schöley

    II Group critique and revision of published figures (1hr) Tim Riffe and others

    * refreshments *

    III Small group critique of participants’ active work (2hrs)

    participants are encouraged to send the organizers a current version of a figure or table with underlying data. We will make a selection to work on in small groups. These will be shared with all participants, as well as the workshop results. Selected participants will be asked to present their problem for ca 3 min before starting group work. This section is then organized as follows:

    problem introductions (30 min)
    work through first set of problems (45 min)
    work through second set of problems (45 min)

    And some commentary on the agenda: part I consists in wise people imparting wisdom. Audrey and Jon (pending) will give broad and general comments and Jonas will give a rigorous presentation on color (where we could all do a better job!). I'll lead up the snarky part II, which will consist in finding published figures or tables in demography journals and improving them. I'll try to keep the variety up! Finally, part III, which we hope will be the bulk of the workshop, will be hands-on. Participants that want to can email us with a project: a figure from a paper in progress that needs some help, an aspect of a poster for this very PAA that still hasn't been printed, a slide from this very PAA that still hasn't been finalized. You'd of course also need to provide the data. If there is a big response we'll have to do a selection, but we'll play it by ear. So you'd present what the goal is and what's been done so far (like 2 or 3 min maybe), and then we'd break into working groups, each led up by one of the presenters/organizers. I expect we can all learn from each other in these excercises. We'll just take it as far as we can in an hour. This is not software-specific, so we'll just make do with what we have. I think we'll get some awesome results!

    Posted Jan 31, 2016, 9:21 AM by Tim Riffe
  • Schoen's 'del', a very fine index if there ever was one
    published on 45th anniversary of the article (August, 1970), with month -precision....

    I've heard Andrew Noymer bring up Schoen's Δ (del) a couple times now in the context of 'good lifetable summary indicators that have been passed over, but without any obvious reason'. Usually it takes three to tip me over, but this time it was two mentions. Maybe because we're talking about demography tools. Well, it should have been one mention!

     Δ is just the geometric mean of a mortality rate schedule, and it has lots of neat properties that you can read about in the short linked article. One of them is that ratios of Δ for two populations (or sexes, or years, etc) can be interpreted in a straightforward way: if the ratio of male Δ to female Δ is 2, then male mortality rates are twice as high. This is not the case for life expectancy or the age standardized death rates. If you halve mortality rates, you don't double life expectancy, and so forth. Age standardized death rates are arbitrary due to the use of a standard (even if some standards are common practice...).

    So here are all Δ in the HMD (or their inverse, actually...), for both sexes (males blue, females red):

    Talk about divergence!!!

    If we want to study trends in divergence / convergence, and if we want to make group comparisons in mortality, there is a good argument that this is the measure we should be using. You can decompose differences in much the same way as we decompose differences in life expectancy, and so forth, partitioning the difference out to ages and causes. Just say'n.

    Here's the code:


    Posted Aug 28, 2015, 5:12 AM by Tim Riffe
  • Tic tocs up, toc ticks down, relativized, averaged
    If you haven't seen the Time Flies page yet, you ought to, it's super cool:

    That viz (can you call it a dataviz? there's no data... concept viz?) got me thinking. The basic notion is that the meaning of a year get's relativized to the amount of time you've lived. As we grow older, the proportion of our life that a given year takes up is less and less. This is all because our reference period (lived life) is growing. Anyway, it's a theoretical optimum, rather than actual perception, but it coincides with the anecdotes people have about time flying faster all the time. I googled a bit and found that plenty of people actually study the perception of time as a function of age. That's awesome.

    I then thought, if you knew how long you'd live, then you'd know how long you have left, and this could be the reference rather than years lived. Let's call this, forward-looking relativized, as opposed to backward-looking relativized. Forward-looking relativization is symmetrical to backward-looking relativization. If you knew when you were going to die, you'd have both durations to relativize to. Then what would you think? How would this change the way you make decisions? Does running out of time make you savor? Does it make you slow down and notice details? At mid life, would we switch perspectives, always referring to the shorter segment of life (the one behind or the one in front). Maybe we'd take an average? But which kind of mean? When you don't know, use the arthmetic mean! And here's how the directionally-averaged perception of a unit of time looks by years lived, years left, and lifespan (in an ATL diagram).

    You'd of course need to weight the lifelines in there, possibly using d(x) from the lifetable, or some other population weights. Plenty of imagining to do in this direction. 

    * In this case, the notions of fast and slow can easily flip, depending on what kind of mean you take ... In fact, even in the given arithmetic representation, you could swap slow and fast, and it'd still be legit. mental yoga.

    Posted Aug 21, 2015, 5:27 AM by Tim Riffe
  • HT #Lotka (1934)
    Today's quote:

    "... the question arises: would not a treatment of demographic problems that based itself on hypotheses in order to extract necessary conclusions be of doubtful practical value? We would be powerfully misled in viewing matters that way. The conditions that present themselves in an actual population are always excessively complicated. Whoever has failed to grasp clearly the necessary relations among the characteristics of a theoretical population subject to simple hypotheses, will certainly be unable to manage in the much more complicated relations that exist in a real population. If one has wavered in the attack on a simple problem, he will assuredly stumble in the face of very serious complications. It is for this reason that authors who profess little respect for the application of mathematical analysis to demographic problems are those who in their writings present us with horrible examples of the confusion that results from striving to resolve by an avalanche of words problems whose complexity imposes on us the use of the condensed language of mathematics." - A. Lotka (1934, 1939, both in French) This translation was from D. P. Smith and H. Rossert (1998)

    True then, true today. HT to VCR for sending me to this manuscript.

    *It turns out to be useful to have a large number of such retorts on hand for the kind of work I do.
    Posted Jul 29, 2015, 8:29 AM by Tim Riffe
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