Sunday, April 29, 2012

Global Trends Graph Updated to 2010

As I'm preparing for my first lecture later this week in CRWF 8000 I'm updating my slides from last semester. I'm using the data we collected for our paper on the 2010 rebound in carbon emissions to update a graph I've used to open a few presentations in the last couple of years:

This introduces the big picture trends of growth energy use and climate change. It's now updated to 2010 showing the rebound from the GFC world recession (or economic slowdown :)). This is just the first slide to be updated. This one looks at emissions in four key countries:

Australia obviously, the two biggest emitters - China and the US - and the UK which industrialized first. The main thing to notice is the continued meteoric rise of emissions in China, which passed the US in 2006 as the largest emitter.

Thursday, April 26, 2012

Seminar @ Crawford School on 29th June

Christian Gross, who will be visiting from the Max Planck Institute of Economics, Jena, Germany, will give the seminar. It will take place in Seminar Room 1, Stanner Building from 12:30 to 1:30.

TITLE: Can Declining Energy Intensity Mitigate Climate Change? Decomposition and Meta-Regression Results

ABSTRACT: Ever since the First Assessment Report on Climate Change by the Intergovernmental Panel on Climate Change (IPCC) in 1990, there is an ongoing debate on the quantification of greenhouse gas emissions for the future. Based on a modified version of the Kaya Identity we argue that the observed reduction in carbon dioxide intensity (CO2/GDP) from 1971 to 2008 was mainly a result of nonrecurring attempts to reduce the energy intensity of production (Energy/GDP) e.g. an extension of the service economy as well as the off-shoring of pollution intensive production. Using meta-significance testing (Stanley, 2005; 2008) based on 80 studies on the relationship between energy and economic growth, we find that, in fact, energy and growth are strongly interlinked, so that a slowdown in the decrease in energy intensity or even a recurring increase is possible. Ceteris paribus, this would also entail an increase in carbon dioxide intensity. We suggest that the only strategy to achieve sustainability is to reduce the multiplier between carbon dioxide intensity and energy intensity, namely the carbon dioxide intensity of energy (CO2/Energy). As a consequence, if our projections are true, the time frame to do so is smaller than normally assumed.

Thursday, April 19, 2012

Great Post on Value of Blogging, Tweeting etc. about Research

Interesting post on the Impact of Social Science Blog. I especially like this graph:

Melissa Terras started tweeting and blogging about papers that she published in the past, which had now been added to her university's depositary. These posts resulted in large increases in downloads for the papers as shown in the graph.

Friday, April 13, 2012

Calculating an Individual Impact Factor Using Scopus

Citation impact factors for journals are widely used to evaluate journal quality, though there is a lot of criticism of the use of this statistic especially to evaluate papers published in those journals. So why not compute an impact factor for an individual researcher rather than for a journal. This is really easy to do using Scopus. Do an "Author Search" and then select "Citation Overview". You will get an output looking like this (minus the green box):

The 2011 five year impact factor is the average citations received in 2011 for papers published by this researcher in the five years 2006-2010. The 2011 citations to articles published in the five year window are highlighted by the green box. There are a total of 47 such citations in this case. And there are 10 articles in the database. So the impact factor is 47/10 = 4.7. The 2010 impact factor was 6.4. Scopus covers more journals in the social sciences than the Web of Science does and so this impact factor is probably not directly comparable to the Journal Citation Report impact factors. In the natural sciences the numbers will be closer.

I think this is definitely worth computing for job or tenure candidates etc. in fields where journal articles dominate. You can't apply it to a new PhD but for those who have done a post-doc etc. or more senior candidates, I can't see why not.

Tuesday, April 10, 2012

Global Warming Preceded by Increasing Carbon Dioxide Concentrations during the Last Deglaciation

So says a paper published last week in Nature by Jeremy Shakun et al. The authors construct new temperature and CO2 series for the last deglaciation period between 22 and 6000 years ago. This is the key figure from the paper:

Clearly the rise in CO2 preceded the main rise in temperature at the end of the ice age. CO2 in the atmosphere also stabilizes before temperature does and most convincingly CO2 falls before the Younger Dryas cold period. I'm actually surprised by the length of the lag.

But the picture is confused by the different behavior of the northern and southern hemispheres. Temperature actually increased in the southern hemisphere before CO2 began to rise:

So based on this data alone perhaps both CO2 and northern hemisphere temperature were driven at different speeds by southern hemisphere temperature.* The authors address this issue with a simulation exercise using an NCAR model. They find they can reproduce the paleotemperature data quite well using greenhouse gases, orbital effects on insolation (amount of sunlight) in the simulation but not so well without the greenhouse gases. This suggests that greenhouse gases do amplify the warming effect due to increased insolation but that they don't initiate deglaciation. This model based evidence is usually considered stronger evidence than empirical time series evidence by climate scientists. But it is the kind of evidence that non-scientists are especially skeptical of.

* Our own paper in Nature in 1997 showed that southern hemisphere temperature Granger caused northern hemisphere temperature in the observational record.

Saturday, April 7, 2012

Ecological Economics Best Paper Prize

Elsevier has offered a prize for a Best Paper Award for Ecological Economics, which we would like to announce or present to the winner at the ISEE Conference in June. The members of the editorial board are supposed to each nominate a paper and then the editor and associate editors will pick the best.

The criteria are to find the "outstanding paper published in Ecological Economics in 2010-2011 that uniquely advances research and praxis in ecological economics."

With more than 500 papers published I'm feeling a bit overwhelmed in coming up with a suggestion. So I was wondering if any of you have any ideas.

Friday, April 6, 2012

Meta-Analysis of Energy-GDP Causality Literature

An interesting paper by Chi-Chung Chen of National Chung-Hsing U., Taiwan and coauthors was recently published in Energy Policy that carries out a meta-analysis of the energy-GDP causality literature.

I've written about this literature on the blog before and originally worked on the topic in my PhD dissertation resulting in a paper published in Energy Economics. I also have a paper I am working on that investigates this issue in our long-run Swedish dataset.*

There is a very large literature on the topic, but as yet no agreed consensus. Studies in this tradition use dynamic time series models to test for Granger Causality or cointegration between energy use and economic output. Studies vary in their methods, the samples they use, what other variables are included in the model etc. Outcomes are either no causality, GDP causes energy, energy causes GDP, or bidirectional or mutual causation.

Chen et al. use a multinomial logit model to assess the effects of various variables on the probability of a study resulting in each of these four outcomes. Here are the key results:

I've edited their table for clarity... The numbers indicate the change in probability of the given outcome for a unit increase of the variable. So researchers are more likely to find that GDP causes energy in developing countries (Develop) and less likely to find that result in OPEC and Kyoto Annex 1 countries where energy causes GDP is more likely to be found. Larger economies though (GDP) are more likely to have GDP causes energy as are studies with more recent data (that including Year 2000) but higher total energy use (EC) is likely to result in a finding of energy causes GDP.

The method variable takes the value of one when a standard Granger Causality test was used and is zero for other methods. Not using the Granger Causality method is more likely to result in a finding of no causality.

I can certainly buy that using different methods can result in different findings if one method is more appropriate than another. But is there really a difference of this sort between countries of these types? Or is something else going on here? My collaborators, Christian Gross and Stephan Bruns are going to be presenting related work at the IAEE Conference in Perth in June. So I'll be writing more about this topic in future...

* This version of the paper that I presented at a workshop in Michigan last year is only an early draft.

Journal of Economic Structures

A new open-access economics journal from Springer. The title is a bit enigmatic but turns out it is the official journal of the Pan-Pacific Association of Input-Output Studies. There are so far few quality open access journals in economics with the leading ones being the Econometric Society's Quantitative and Theoretical Economics. And, of course, the Journal of Economic Perspectives is also open access now. There are other open access journals in economics of course but they don't have the reputation of these. And the B.E. journals seem to have become non-open access and were never quite that model anyway. In my opinion, there is less momentum to open access in economics than in biology say because of the strong working paper culture in economics means that most papers do have a free version available on the web and the role of funders in pushing open access is much smaller as funding dollars are much less important in economics.

Thursday, April 5, 2012

Google Scholar Metrics

Google Scholar has just released metrics for journals. The main indicator is an h-index for the period 2007-2011. The top list of all publications (in English) strangely lists RePEc and arXiv as the 4th and 5th top journals. RePEc is certainly not a journal, MPRA could be considered as a journal, I suppose, but it's not listed and neither is SSRN. Another interesting result is that Ecological Economics is the fourth ranked journal with the term "economic" in its title! I don't think that passes the "laugh test" as far as mainstream economists are concerned.

Monday, April 2, 2012

Top Three Crawford Working Papers in March 2012

This month, I decided to do something a little different and just highlight the three most downloaded papers:

Total Factor Productivity and Economic Growth in Indonesia, Pierre van der Eng, 27 downloads.

Adaptation to climate change: Formulating policy under uncertainty, Leo Dobes, 24 downloads.

Impacts of border carbon adjustments on China's sectoral emissions: simulations with a dynamic computable general equilibrium model, Qin Bao, Ling Tang, ZhongXiang Zhang, Han Qiao and Shouyang Wang, 23 downloads.

Total downloads were 793 with 2471 abstract views across the six active series.