Skip to main content

Home/ Long Game/ Group items tagged contrarian

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
anonymous

Freakonomics: What Went Wrong? - 0 views

www.americanscientist.org/...issue.aspx

shared by anonymous on 13 Dec 11 - Cached
  • Oster’s work stirred debate for a few years in the epidemiological literature, but eventually she admitted that the subject-matter experts had been right all along. One of Das Gupta’s many convincing counterpoints was a graph showing that in Taiwan, the ratio of boys to girls was near the natural rate for first and second babies (106:100) but not for third babies (112:100); this pattern held up with or without hepatitis B. In a follow-up blog post, Levitt applauded Oster for bravery in admitting her mistake, but he never credited Das Gupta for her superior work. Our point is not that Das Gupta had to be right and Oster wrong, but that Levitt and Dubner, in their celebration of economics and economists, suspended their critical thinking.
  • In SuperFreakonomics, Levitt and Dubner use a back-of-the-envelope calculation to make the contrarian claim that driving drunk is safer than walking drunk, an oversimplified argument that was picked apart by bloggers. The problem with this argument, and others like it, lies in the assumption that the driver and the walker are the same type of person, making the same kinds of choices, except for their choice of transportation.
  • Such all-else-equal thinking is a common statistical fallacy. In fact, driver and walker are likely to differ in many ways other than their mode of travel. What seem like natural calculations are stymied by the impracticality, in real life, of changing one variable while leaving all other variables constant.
  • ...8 more annotations...
  • This unavoidable tradeoff between false positive and false negative errors is a well-known property of all statistical-prediction applications. Circling back to check all the factors involved in the problem might have helped the authors avoid this mistake.
  • How could an experienced journalist and a widely respected researcher slip up in so many ways? Some possible answers to this question offer insights for the would-be pop-statistics writer.
  • Leave friendship at the door: We attribute many of these errors to the structure of the authors’ collaboration, which, from what we can tell, relies on an informal social network that has many potential failure points.
  • Don’t sell yourself short: Perhaps Levitt’s admirable modesty—he has repeatedly attributed his success to luck and hard work rather than genius—has led him astray. If he feels he is surrounded by economists more exceptional and brilliant than he is, he may let their assertions stand without challenge.
  • Maintain checks and balances: A solid collaboration requires each side to check and balance the other side. Although there’s no way we can be sure, perhaps, in some of the cases described above, there was a breakdown in the division of labor when it came to investigating technical points.
  • Take your time: Success comes at a cost: The constraints of producing continuous content for a blog or website and meeting publisher’s deadlines may have adverse effects on accuracy.
  • Be clear about where you’re coming from: Levitt’s publishers, along with Dubner, characterize him as a “rogue economist.”
  • Use latitude responsibly: When a statistician criticizes a claim on technical grounds, he or she is declaring not that the original finding is wrong but that it has not been convincingly proven. Researchers—even economists endorsed by Steven Levitt—can make mistakes. It may be okay to overlook the occasional mistake in the pursuit of the larger goal of understanding the world. But once one accepts this lower standard—science as plausible stories or data-supported reasoning, rather than the more carefully tested demonstrations that are characteristic of Levitt’s peer-reviewed research articles—one really has to take extra care, consider all sides of an issue, and look out for false positive results.
  • anonymous on 13 Dec 11
     
    In our analysis of the Freakonomics approach, we encountered a range of avoidable mistakes, from back-of-the-envelope analyses gone wrong to unexamined assumptions to an uncritical reliance on the work of Levitt's friends and colleagues. This turns accessibility on its head: Readers must work to discern which conclusions are fully quantitative, which are somewhat data driven and which are purely speculative.
anonymous

How close are we to catastrophic climate change? - 0 views

www.scientificamerican.com/...post.cfm

climate sustainability longnow

shared by anonymous on 01 Jul 10 - Cached
  • As you may have noticed, scientists remain convinced that humans are altering the global climate with an excess of greenhouse gas emissions—soot, methane and the ever-present carbon dioxide we pump out from our lungs and coal-burning power plants. The question is: how bad is said climate change going to get?
  • The interviewed experts don't expect to be any more able to understand clouds and the other uncertainties by 2030—even if funding for such research were tripled in the next 20 years. That matches real world results, since the experts interviewed back in the 1990s were just as uncertain about clouds and the like as when re-interviewed in the 2000s. Or, as climatologist Stephen Schneider of Stanford University, one of the experts interviewed this time and last, told me last year: "We don't know much more than we did in 1975" about climate sensitivity.
  • Fortunately, as investor Vinod Khosla is fond of saying (about himself and others): "Experts are usually wrong" when it comes to forecasting the future. Let's hope he's right about that at least, in this case.
  • anonymous on 01 Jul 10
     
    By David Biello at Scientific American Observations on June 28, 2010.
anonymous

Attention Whole Foods Shoppers - 0 views

www.foreignpolicy.com/...attention_whole_foods_shoppers

sustai sustainability contrarian longnow

shared by anonymous on 29 Apr 10 - Cached
  • Food has become an elite preoccupation in the West, ironically, just as the most effective ways to address hunger in poor countries have fallen out of fashion.
  • Yet 850 million people in poor countries were chronically undernourished before the 2008 price spike, and the number is even larger now, thanks in part to last year's global recession. This is the real food crisis we face.
  • Poverty -- caused by the low income productivity of farmers' labor -- is the primary source of hunger in Africa, and the problem is only getting worse. The number of "food insecure" people in Africa (those consuming less than 2,100 calories a day) will increase 30 percent over the next decade without significant reforms, to 645 million, the U.S. Agriculture Department projects.
  • ...9 more annotations...
  • Influential food writers, advocates, and celebrity restaurant owners are repeating the mantra that "sustainable food" in the future must be organic, local, and slow. But guess what: Rural Africa already has such a system, and it doesn't work. Few smallholder farmers in Africa use any synthetic chemicals, so their food is de facto organic. High transportation costs force them to purchase and sell almost all of their food locally. And food preparation is painfully slow. The result is nothing to celebrate: average income levels of only $1 a day and a one-in-three chance of being malnourished.
  • we need to de-romanticize our view of preindustrial food and farming. And that means learning to appreciate the modern, science-intensive, and highly capitalized agricultural system we've developed in the West.
  • It's true that the story of the Green Revolution is not everywhere a happy one. When powerful new farming technologies are introduced into deeply unjust rural social systems, the poor tend to lose out.
  • Traditional food systems lacking in reliable refrigeration and sanitary packaging are dangerous vectors for diseases. Surveys over the past several decades by the Centers for Disease Control and Prevention have found that the U.S. food supply became steadily safer over time, thanks in part to the introduction of industrial-scale technical improvements.
  • The American Journal of Clinical Nutrition last year published a study of 162 scientific papers from the past 50 years on the health benefits of organically grown foods and found no nutritional advantage over conventionally grown foods. According to the Mayo Clinic, "No conclusive evidence shows that organic food is more nutritious than is conventionally grown food."
  • Less than 1 percent of American cropland is under certified organic production. If the other 99 percent were to switch to organic and had to fertilize crops without any synthetic nitrogen fertilizer, that would require a lot more composted animal manure. To supply enough organic fertilizer, the U.S. cattle population would have to increase roughly fivefold. And because those animals would have to be raised organically on forage crops, much of the land in the lower 48 states would need to be converted to pasture. Organic field crops also have lower yields per hectare. If Europe tried to feed itself organically, it would need an additional 28 million hectares of cropland, equal to all of the remaining forest cover in France, Germany, Britain, and Denmark combined.
  • between 1990 and 2004, food production in these countries continued to increase (by 5 percent in volume), yet adverse environmental impacts were reduced in every category. The land area taken up by farming declined 4 percent, soil erosion from both wind and water fell, gross greenhouse gas emissions from farming declined 3 percent, and excessive nitrogen fertilizer use fell 17 percent. Biodiversity also improved, as increased numbers of crop varieties and livestock breeds came into use.
  • Foreign assistance to support agricultural improvements has a strong record of success, when undertaken with purpose. In the 1960s, international assistance from the Rockefeller Foundation, the Ford Foundation, and donor governments led by the United States made Asia's original Green Revolution possible.
  • Development skeptics and farm modernization critics keep pushing us toward this unappealing second path. It's time for leaders with vision and political courage to push back.
  • anonymous on 29 Apr 10
     
    By Robert Paarlberg at Foreign Policy on May/June 2010. Hat tip from Modeled Behavior (http://modeledbehavior.com/2010/04/28/in-defense-of-the-industrial-farm-and-against-local-sustainable-and-organic/) - Printable, full version
anonymous

Attention Whole Foods Shoppers - 0 views

www.foreignpolicy.com/...attention_whole_foods_shoppers

sustainability contrarian

shared by anonymous on 29 Apr 10 - Cached
  • anonymous on 29 Apr 10
     
    By Robert Paarlberg at Foreign Policy on May/June 2010. Hat tip from Modeled Behavior (http://modeledbehavior.com/2010/04/28/in-defense-of-the-industrial-farm-and-against-local-sustainable-and-organic/)
1 - 4 of 4
Showing 20▼ items per page