Author Archives: rdmyers75@hotmail.com

connectivity and corridors

From Conservation Biology, here’s an article on connectivity and movement corridor models for wildlife:

Habitat corridors are important tools for maintaining connectivity in increasingly fragmented landscapes, but generally they have been considered in single-species approaches. Corridors intended to facilitate the movement of multiple species could increase persistence of entire communities, but at the likely cost of being less efficient for any given species than a corridor intended specifically for that species. There have been few tests of the trade-offs between single- and multispecies corridor approaches. We assessed single-species and multispecies habitat corridors for 5 threatened mammal species in tropical forests of Borneo. We generated maps of the cost of movement across the landscape for each species based on the species’ local abundance as estimated through hierarchical modeling of camera-trap data with biophysical and anthropogenic covariates. Elevation influenced local abundance of banded civets (Hemigalus derbyanus) and sun bears (Helarctos malayanus). Increased road density was associated with lower local abundance of Sunda clouded leopards (Neofelis diardi) and higher local abundance of sambar deer (Rusa unicolor). Pig-tailed macaque (Macaca nemestrina) local abundance was lower in recently logged areas. An all-species-combined connectivity scenario with least-cost paths and 1 km buffers generated total movement costs that were 27% and 23% higher for banded civets and clouded leopards, respectively, than the connectivity scenarios for those species individually. A carnivore multispecies connectivity scenario, however, increased movement cost by 2% for banded civets and clouded leopards. Likewise, an herbivore multispecies scenario provided more effective connectivity than the all-species-combined scenario for sambar and macaques. We suggest that multispecies habitat connectivity plans be tailored to groups of ecologically similar, disturbance-sensitive species to maximize their effectiveness.

Ebola

The Ebola situation makes for some scary headlines. From the CDC, the number of cases as I write this (July 31) in Guinea, Liberia, and Sierra Leone is 1,322 of which 728 (55%) have died.

Ebola is a disease with no known cure which incubates in bats. To put these numbers in perspective, Wikipedia says that 8,231 people in Haiti have died of cholera since 2010, a disease we know the exact cause of and exactly how to prevent (clean drinking water) and treat (staying hydrated with clean drinking water).

R and NetLogo

I had never heard of Netlogo, which is a programming language for simulating and teaching agent based models. Agent-based modeling is important because it might be the key to real quantitative simulation in economics and the social sciences. You can keep drilling down into the links in this post from R-bloggers until you either run out of time or find out everything you want to know about it.

Lords of Finance

Lords of Finance: The Bankers Who Broke the World

This book was kind of a hard read, but I’m glad I read it. My favorite part of the book was the last five pages, particularly these quotes explaining just how bad the Depression really was.

Anyone who writes or thinks about the Great Depression cannot avoid the question: Could it happen again? First it is important to remember the scale of the economic meltdown that occurred in 1929 to 1933. During a three-year period, real GDP in the major economies fell by over 25 percent, a quarter of the adult male population was thrown out of work, commodity prices fell in half, consumer prices declined by 30 percent, wages were cut by a third. Bank credit in the United States shrank by 40 percent and in many countries the whole banking system collapsed. Almost every major sovereign debtor among developing countries and in Central and Eastern Europe defaulted, including Germany, the third largest economy in the world. The economic turmoil created hardships in every corner of the globe, from the prairies of Canada to the teeming cities of Asia, from the industrial heartland of America to the smallest village in India. No other period of peace time economic turmoil since has even come close to approaching the depth and breadth of that cataclysm…

[The Great Depression was] a crisis equivalent in scope to the combined effects and more of the 1994 Mexican peso crises, the 1997-98 Asian and Russian crises, the 2000 collapse in the stock market bubble, and the 2007/8 world financial crisis, all cascading upon one and other in a single concentrated two-year period. The world has been saved in part from anything approaching the Great Depression because the crises that have buffeted the world economy over the past decade [writing in 2009] have conveniently struck one by one, with decent intervals in between.

computer algorithm can identify dogs

Microsoft has posted this video on Youtube of new software that can identify a dog breed from a photo of a dog.

Why does this matter? Well, it looks like computers are getting better and better at doing things that human beings have always been better at. It’s easy to think of all sorts of disturbing intelligence and military applications, but also great scientific applications like sending a drone to inventory all the trees in a forest or fish in a lake.

nurse trees

I find the idea of “nurse trees” interesting. From Wikipedia:

A nurse tree is a larger, faster-growing tree that shelters a smaller, slower-growing tree or plant. The nurse tree can provide shade, shelter from wind, or protection from animals who would feed on the smaller plant.

Eventually the younger plant outcompetes the older one, and the older one dies, or I suppose it can be cut down by humans. I am thinking about how to apply these ecological concepts to give a helping hand in more urban areas. In my professional work on stormwater management, we often dig up urban soils and replace them with a manufactured soil mix that is more permeable to water and better for plant growth. But all that digging and trucking and waste disposal has a cost and an environmental impact, when we are doing all this to try to help downstream water quality. Maybe we can use carefully chosen trees or plants early on to loosen and add organic matter to the urban soils, then come back a year or two later and plant the trees and plants that we want for the long term. Even better if there is some plant mix where the first phase is faster growing, but then gradually gets out-competed by the second phase, just like the nurse tree concept described above.

autonomous vehicles

Here are two articles on autonomous vehicles: a short one from Streetsblog USA saying they might just mean people will choose to live even further from work, and a long one from Eno Center for Transportation going into very detailed examination of potential costs and benefits.

My thoughts on the first possibility are that this may indeed happen. Some people might try to live way off in the countryside and not mind several hours in the car each day because they can now spend it sleeping, reading, working, being entertained or being social. Some people will like this idea and some will not. Some will like it but make the decision based on financial cost. Let’s remember that government policy is important here – if we tax people in cities and use that money to subsidize highways to the countryside, more people will choose to live in the countryside because the cost (to them) is lower, while the true cost is hidden. Also, if too many people decide to live in the countryside, it will not be countryside any more.

Here’s a quote from the second article:

AVs have the potential to fundamentally alter transportation systems by averting deadly crashes, providing critical mobility to the elderly and disabled, increasing road capacity,
saving fuel, and lowering emissions. Complementary trends in shared rides and vehicles may lead us from vehicles as an owned product to an on-demand service. Infrastructure
investments and operational improvements, travel choices and parking needs, land use patterns, and trucking and other activities may be affected. Additionally, the passenger compartment may be transformed: former drivers may be working on their laptops, eating meals, reading books, watching movies, and/or calling friends – safely.

After mentioning land use in this paragraph, the report never really returns to it, focusing instead on “congestion”. I think the potential for radical land use transformation is the biggest story related to autonomous vehicles, so the fact that it is left out of a report like this illustrates how critical it is to have the urban and regional planning profession involved alongside traditional minded transportation engineers.

informal economies

I’m somewhat interested in the idea of informal economies. According to this paper from the National Bureau of Economic Research, economists tend to think they’re bad – either a cause of poverty and slow development, or a symptom of it:

We establish five facts about the informal economy in developing countries. First, it is huge, reaching about half of the total in the poorest countries. Second, it has extremely low productivity compared to the formal economy: informal firms are typically small, inefficient, and run by poorly educated entrepreneurs. Third, although avoidance of taxes and regulations is an important reason for informality, the productivity of informal firms is too low for them to thrive in the formal sector. Lowering registration costs neither brings many informal firms into the formal sector, nor unleashes economic growth. Fourth, the informal economy is largely disconnected from the formal economy. Informal firms rarely transition to formality, and continue their existence, often for years or even decades, without much growth or improvement. Fifth, as countries grow and develop, the informal economy eventually shrinks, and the formal economy comes to dominate economic life. These five facts are most consistent with dual models of informality and economic development.

I’ve never bought into the idea that informal economies are 100% bad. I’ve been very lucky to spend some time in central Thailand, right on the edge between a rural and urban area, and to experience a mix of the informal and formal economies. It makes perfect sense that higher-tech sectors like mining, manufacturing, banking, and so forth are run by efficient, formal, corporations. But lower-tech service sectors provide a chance for “poorly educated entrepreneurs” (a pretty condescending term, actually) to provide everyday goods and services to each other at low cost and practically no overhead. Why is it “efficient” to pay $10 for a tasteless corporate meal at the mall, with most of that money going to pay rent to a real estate corporation and its army of lawyers, accountants, human resourcers, and insurance agents, plus the gas and wasted time to get there, vs. $2 for a tastier meal from a neighborhood entrepreneur? When you stop and chat with your neighbor, that’s culture and social capital, not “inefficiency”. And when something bad happens, you and the neighbor are going to lean on each other for help, not the lawyers and accountants working for the faceless corporation that runs the mall.

the killer robots are coming, seriously

Wired says the robot future is really, truly almost here:

The robots are coming, and they’re getting smarter. They’re evolving from single-task devices like Roomba and its floor-mopping, pool-cleaning cousins into machines that can make their own decisions and autonomously navigate public spaces. Thanks to artificial intelligence, machines are getting better at understanding our speech and detecting and reflecting our emotions. In many ways, they’re becoming more like us.

There are a couple new and disturbing things I learned from this article. First, military drone technology has moved to police departments and corporate security departments. One example is

the Skunk Riot Control Copter, a drone armed with plastic bullets and pepper spray. The Guardian recently reported that the South African company that builds the Skunk has been selling it to an international mining company interested in using it to suppress labor riots.

There is also a developing robot sex industry, which I suppose should not be a surprise.