Playing with Google Scholar Citations

Google Scholar Citations has only been public for 10 days but already an analysis has appeared. I hadn't thought of searching by institution myself but this is a good idea. For example:

Australian National University
CSIRO

This means that it is now easy to construct a kind of h-index for institutions: where h is the number of authors cited h times. ANU's h-index is 37: and CSIRO's is 58. Of course, this is very early days and not many people have signed up yet. Harvard scored 141. I suspect based on this that something along the lines of the Wu-index (Wu = n where n is the number of articles cited 10n times) or some other variant is going to be more useful.

Bob Gregory on the Mining Boom

Over the weekend I attended the 2011 PhD Conference in Economics and Business at the University of Queensland. This is an annual event held at ANU, UWA, and now UQ that has apparently been running for 24 years. Final year PhD students from across Australia present papers each of which has a faculty discussant. I was discussing Marjan Nazifi's paper on convergence (or lack of it) between EUA and CER permit prices on the European carbon exchange. My student Md Shahiduzzaman was also presenting a paper on interfuel substitution in Australia.

There was also a conference keynote given by Bob Gregory based on his paper with Peter Sheehan on the Australian mining boom. The key figure is this one:



which shows the gap that has opened up between Gross Domestic Income and Gross Domestic Product since 2003 due to the increase in the terms of trade. The increase in prices of minerals have boosted nominal mining income but this isn't reflected in the GDP numbers. I am still trying to get my head around the technicalities of this. It seems to be another case of where you need to be very careful about how national accounts are computed.

Debate on Australia's Coal Exports

I was featured along with Frank Jotzo and others in this blogpost on DotEarth by Andy Revkin. I'm still confused about why people want Australia to go beyond its obligations under the UNFCCC. And it's not as if China isn't doing its part too, though very soon China will need to start reducing emissions rather than just emissions intensity. Wait to be surprised on that count I think.

Daron Acemoglu on Publishing

Advice from Daron Acemoglu - editor of Econometrica and Clark Medal winner - on how to write papers and get published.

Tom Stanley's Presentation at the Wiley Online Economics Conference

See Tom Stanley's presentation on meta-analysis. There is also a commentary by Randall Rosenberger and a free "virtual issue" of the Journal of Economic Surveys.

Google Scholar Citations Now Open to All

Google Scholar Citations is a new academic profile service that is very similar to Researcher ID but using Google Scholar citations instead. The service has been in limited release but now is open to everyone. I found that I didn't need to make too many edits to my profile. The main issue is the entries which are prefaced by "[Citation]" in Google Scholar. These are sources that Google Scholar has found cited in publications but cannot find on the web. Most of these are not included in my profile and I couldn't add all of them. As a result my H-Index in the profile is one point lower than the number I computed direct from Google Scholar. The total citation count is 0.5% lower than what I found with my manual search in Google Scholar. Overall, I think this is a great innovation though I would like to be able to get a bit more access to the numbers of citations per year rather than just having a graph at the top of the profile. Still, I'm sure it is early days at this point.

New Journal: Ecosystem Services

A new journal from Elsevier with an editorial board with a lot of well-known names from ecological economics. From the homepage:

Ecosystem Services, associated with Ecosystem Services Partnership (ESP), is an international, interdisciplinary journal that deals with the science, policy and practice of Ecosystem Services in the following disciplines: ecology and economics, institutions, planning and decision making, economic sectors such as agriculture, forestry and outdoor recreation, and all types of ecosystems.

The aims of the journal are:
(1) to improve our understanding of the dynamics, benefits and social and economic values of ecosystem services,
(2) to provide insight in the consequences of policies and management for ecosystem services with special attention to sustainability issues,
(3) to create a scientific interface to policymakers in the field of ecosystem services assessment and practice, and
(4) to integrate the fragmented knowledge about ecosystem services, synergies and trade-offs, currently found in a wide field of specialist disciplines and journals.

From Correlation to Granger Causality Added to New Crawford School Research Papers Series

My paper From Correlation to Granger Causality has been added to the Crawford School Research Papers series on RePEc. I'm now working on revising the paper and doing new tests in collaboration with Kerstin Enflo. This version represents the conference paper I gave in Michigan at the "Annual Institute on Joint Outcomes for Sustainability" (which was not an annual institute but a once off workshop) organized by Arun Agrawal. Both Shuang and myself were invited to the workshop. Shuang's work was more directly relevant looking at decision-making for dealing with invasive species. I was asked to talk about "from correlation to causal inference" in a session of that topic where different econometric methods were discussed. Most relevant in that session to the topic at hand was Paul Ferraro's presentation on the effects of protected areas in Costa Rica on poverty in surrounding districts.

Google Scholar Continues to Improve

Every few months Google Scholar seems to undergo a rebuild of their database and housekeeping exercise. Before the exercise, lists of references are no longer in exact order of the number of citations they have received. Rather they are in order of the number they received at the last rebuild. Another rebuild has occurred today. In this rebuild they have managed to aggregate together stray citations much better than ever before. All the citations to my two most cited articles (both in World Development) have now been aggregated into single entries in the database rather than being spread across several entries with slightly different bibliographic data. I don't know whether accuracy has similarly improved in terms of number of citations. Previously, there could be some double counting of the same paper in the list of citations to an article. It's likely that that has improved too. There are still some split entries but it is much better than before and should be much more user-friendly for counting h-indices etc.

Schmith, Johansen, and Thejll on Atmospheric Temperature and Sea Level Rise

Three Danish researchers, including famous time series econometrician Soren Johansen, recently posted a paper on SSRN on a cointegration analysis of atmospheric temperature, sea level, and radiative forcing. The study has some odd results. From their abstract:

"We find a relationship between sea level and temperature and find that temperature causally depends on the sea level, which can be understood as a consequence of the large heat capacity of the ocean."

They find that sea level is an exogenous variable and drives atmospheric temperature. I think this is a plausible explanation for this result given that the data is annual and as they say later in the abstract:

"We hypothesize that this is due to a long adjustment time scale of the ocean and show that the number of years of data needed to build statistical models that have the relationship expected from physics exceeds what is currently available by a factor of almost ten."

The slow adjustment of the ocean to changes in radiative forcing is a major challenge for time series modelling of the global climate system using historical data. I debated Michael Beenstock on this issue last year on this blog and in an e-mail exchange with him. The problem is that as Schmith et al. find here the atmospheric temperature depends on the temperature of the ocean. Directly modelling the effect of radiative forcing on the atmospheric temperature using a short time series can result in biased estimates. My approach was to use ocean heat content as an additional variable that acts as a second transmission path for the effects of radiative forcing changes on atmospheric temperature. Using sea level might work in a similar way though it depends on glacier melt and other factors potentially as well as thermal expansion of the ocean. An advantage of sea level is that a much longer time series is available.

Schmith et al.'s stranger result is:

"In a second step, we use the total radiative forcing as an explanatory variable, but unexpectedly find that the sea level does not depend on the forcing."

I would have expected them to find an effect of radiative forcing on sea level. But using a Monte Carlo analysis they argue that it would take 1000 years of data to get a significant result.

I'm not sure that this is the final word that can be said on this. They find only one long relationship between the three key variables.* This relationship is as follows:

zt = Tt - 1.4 St - 0.3 Ft

zt is the residual in year t, T is atmospheric temperature, S is sea level, and F is radiative forcing. My problem is that this doesn't make sense to me physically as an equilibrium relationship. It could make sense that there are long-run relationships between T and S, between S and F, and between T and F. But, as written, sea level can substitute for forcing in affecting atmospheric temperature and vice versa. I suspect that this result is because the volcanic events render the forcing series relatively stationary and, therefore, cointegration cannot be rejected for this relationship. The forcing series looks like this:



In my work, I instead assumed which variables had long-run relationships based on physical theory and I used a multicointegration type approach. So I'm not surprised that sea level doesn't react to this disequilibrium in their analysis. I would be interested in what results they get if they also test a forcing series without the volcanic effects or disaggregate the stationary (volcanics) and non-stationary (GHGs, aerosols, solar irradiation) forcing components.

Of course, this relationship might actually make sense and I could be totally wrong here. Let me know what you think.

I'm really happy, though, that time series analysis is increasingly being used now to investigate these questions. Robert Kaufmann and I pretty much pioneered this but I gave up as I found it hard to get much positive interest from climate modellers. I never published my final paper on the topic. Robert Kaufmann has continued to work on this with greater success.

* In the paper there is a typo where they say that the p-value for the test of one cointegrating vector against two is 0.01. It is in fact 0.9117 the authors tell me in an e-mail.

Paper Accepted by AJARE

My paper with Jack Pezzey and Ross Lambie: "Where in the world is it cheapest to cut carbon emissions?" has been accepted for publication by the Australian Journal of Agricultural and Resource Economics. It will be a while till it is available online. In the meantime there is a working paper version available here. The paper arose from the observation that countries like Australia which at first glance seem to use energy wastefully and have abundant opportunities to cut emissions at low costs can have high total costs of addressing climate change because they are so emissions intensive. Where it is cheap to cut emissions depends on whether we rank countries by marginal costs of reducing emissions or by total costs of reducing emissions.

In the paper, we test this idea using the results of the models that participated in the EMF-22 climate policy simulation exercise and the results seem to support this conjecture. This might explain both debates within countries about what to do about climate change and the different stances of countries in the international negotiations. For example environmentalists might look at the cheap ways (in the marginal sense) to cut emissions in countries like Australia and be outraged that they're not happening while business might look at the total costs of meeting a given policy...

Also the paper gives estimates of the marginal abatement cost curve for the 4 main countries/regions based on the consensus of existing models. They show that to get substantial cuts in emissions on the order of the Copenhagen pledges you would need carbon prices a lot above the $23 initial price of the Australian ETS. The models might be over-estimating the cost of abatement. But when you take into account the half of Australian abatement expected to come from offsets and the amount that will be removed by direct action (RET) the amount of remaining domestic abatement required is in the ballpark of this kind of price.

ARC Announces DECRAs and Future Fellows

Only two Future Fellowships were awarded in economics. Benno Torgler (QUT) got one for "The role of moral sentiments and emotions in human nature: an interdisciplinary empirical approach". Michael Smith at Uni Melbourne got one for an econometric theory project. Obviously, it wasn't the turn of economics...

John Tang at College of Business and Economics got a DECRA to work on "Understanding industrialisation, entrepreneurship, and technology adoption in emerging economies: new evidence from historical Japanese firms". This is the only economics award ANU got in this round of announcements.

Estimating Cointegration Models with Structural Breaks

The Johansen cointegration procedure is one of the most popular methods of testing for cointegration. The tests and estimation are carried out by restricting a vector autoregression model. One of the key issues is deciding on the types of time trends and constant terms to include in the model. This is important because the distribution of the test statistics is different for each possible combination. The basic versions of the procedure assume that any linear time trend has a constant slope. But in reality the slope of the trend - which might represent a variable such as technological change - might not be constant. Johansen et al., 2000 investigated this issue and derived test distributions for the case where there are known structural breaks that cause the trend to change slope as well as for shifts in the model intercepts too. If you use EViews there seems to be a fairly user friendly way of carrying out these tests and estimating the model provided by David Giles at University of Victoria (Canada). David also has a lengthy blogpost explaining how to carry out this kind of analysis.

Reference:

Johansen, S., Mosconi, R. and B. Nielsen (2000), Cointegration Analysis in the Presence of Structural Breaks in the Deterministic Trend, Econometrics Journal, 3, 216- 249.

Crawford School Research Papers

I often post about our CCEP Working Paper series. We also have a new Crawford School Research Paper series that unifies the previous paper series from various Crawford School entities. The series is starting to get a decent amount of downloads and abstract views.

Does Open Access Increase Citations?

PLoS ONE has a high impact factor despite publishing 70% of submitted papers. It is, of course, the best known open access journal. Does open access increase the rate of citation? The naive answer would be that it must obviously do so. Taking a barrier to access away must result in more people reading and citing a paper. On the other hand most research libraries are going to subscribe to the top journals in each field so this might be more important for lower ranked journals than highly ranked journals. Analysis can also be confounded if higher quality articles are submitted to open access journals as is argued for PLoS ONE due to its publication fee. A 2006 article in PLoS Biology compared open access and non-open access articles in the same journal - PNAS - and concluded that the open access articles were cited more. But more recent research across broader samples of journals seems to be mixed. I haven't done any detailed research on this but need to include something on this in a presentation on Friday. Any feedback would be welcome.

6. The Energy Cost Share Declines Over Time

This fact is at the moment only supported by the data from Sweden and so isn't much of a fact. In Sweden the share of costs represented by energy use has declined over time:



It seems that this might be a general phenomenon. I have seen references elsewhere to a declining income share for land too. The implication is that the elasticity of substitution between energy and other inputs is different from unity. Stern and Kander show it to be about 0.65 in Sweden.

5. Energy Intensity Declines Over Time

Though energy use has generally increased over time it has grown more slowly than has GDP. Globally it grew at about half the rate of GDP in the last 30 years. As a result energy intensity (energy per dollar of GDP) has declined globally:



Energy intensity has declined in most key countries. This chart shows the trends from 1971 to 2007:



Note that though China was very energy intensive in the 1970s, India was not. Hence there was not a lot of correlation between income per capita and energy intensity back then either. In fact (as Stephen Howes raised at my seminar on Tuesday) energy intensity has increased in some countries over time. These appear to be mostly in Latin America. We don't see this trend in any developed country. So it is a stylized but not universal fact that energy intensity has declined over time.

When we ignore traditional sources of energy such as biomass and animal power a very different pattern emerges:



As fossil fuel use was once zero in most countries (some countries have used coal for a very long time) energy intensity based on only modern energy sources must also have been zero and then increased. This results in an inverted U shape path as shown in this chart.

4. Energy/Capital is Negatively Correlated with GDP per Capita

I've blogged about the energy capital ratio before. Here is a snapshot for 85 non-oil producing countries in 2007:



There is a much stronger relationship here than for energy intensity... This suggests that this indicator is maybe closer to a measure of true energy efficiency. Astrid Kander shows that the inverse - capital/energy - it also has risen over long-run:

3. Energy Intensity is not Correlated with GDP per Capita

As you can see from the chart this claim is only partially true. Energy intensity (energy per dollar of GDP) does seem somewhat higher in the less developed countries. But energy intensity does not seem to vary across middle and high income countries. As GDP per capita is very closely related to output per worker, otherwise known as labor productivity (the productivity number the media is often talking about) it's curious that there is no relationship. This suggests that energy intensity is not a good proxy for energy efficiency in an underlying technological sense. My main environmental economics research hub paper discusses this issue at length. I find that underlying energy efficiency varies much more with GDP per capita than does energy intensity but a bunch of other factors including climate and economic structure also affect energy intensity. Countries like China that use a lot of coal are going to be more energy intensive, for example, because coal is a lower quality - a less productive - fuel than oil or natural gas.

As RePEc Grows Downloads per Person Continue to Decline

I first reported on this issue a couple of years ago. The trend continues:



As RePEc membership and the number of items online continues to grow, the number of abstract views and downloads per person continues to fall. The chart shows abstract views and downloads each month per RePEc member. The number of downloadable or viewable items per member is actually constant or rising. Possible explanations are:

1. The average quality of papers is declining - assuming better economists joined earlier on average.

2. Too much supply relative to demand. The total community of economists doesn't expand as fast as the number of RePEc members.

3. Of course, the average paper is getting older and older papers will be downloaded less.

4. A lot of people's papers were already on RePEc as journal articles and also working papers but they weren't registered. They are not adding papers as they register and so the number of downloads per person registered is declining.

5. A new phenomenon is that total downloads and abstract views have begun to fall:



Maybe this is attributable to improvements in Google Scholar and other means of finding papers that bypass RePEc?

Whatever the cause, a given number of abstract views or downloads is getting a higher RePEc ranking over time.

2. Energy Use Per Capita Increases With GDP Per Capita

Because energy is used to transform and transport matter and energy must be extracted from the environment and then returned to it in waste form, energy use can be seen as a rough proxy for environmental impact in general. Of course, some forms of energy use are more environmentally disruptive than others and some things we can do with energy are worse then others. There is a clear linear relationship here between the logs of income and energy use per capita. There is again no sign of an environmental Kuznets curve.

Sovereign Wealth Fund as a Solution to the Dutch Disease?

Yesterday, Max Corden gave a public lecture on the topic "The Dutch Disease in Australia: Policy Options for a Three-Speed Economy". A working paper is available here. Corden was a pioneer in the analysis of the Dutch Disease. This is where a booming mining sector leads to an appreciation of the exchange rate and a negative impact on other tradables sectors of the economy. "Dutch" refers to the natural gas boom in the Netherlands in the 1950s. Australia is currently suffering from this Dutch Disease.

He laid out three potential policies:

1. Do nothing
2. Protect the suffering industries
3. Sovereign wealth fund invested overseas

The idea of the SWF is that the outflow of capital will put negative pressure on the exchange rate. Of course, he didn't like policy #2. But in the end Corden was ambivalent between options #1 and #3. However, he recognizes that there is a push for option 2 and, therefore, promoting an SWF might help head-off that push.

Only 26 DORA's Were Awarded Australiawide

It turns out that the ARC only made 26 Discovery Outstanding Researcher Awards in this funding round. The consultation paper that the ARC put out before the changes to the scheme had proposed awarding up to 70 DORA's per year.

CCEP Working Papers in October 2011

This was a great month for CCEP Working Papers with a large number of downloads and abstract views. In fact, we had the highest number of downloads per paper in the world. And the series is ranked third over the last 12 months.

We also had a new paper from Frank Jotzo and Peter Wood titled: Fulfilling Australia's international climate finance commitments: Which sources of financing are promising and how much could they raise?. This paper was downloaded 202 times and was a major contributor to the month's results. The other big contribution to downloads was the guest blogpost I did on the Oil Drum, which discussed my paper on the role of energy in economic growth. This generated 387 downloads! A recent much discussed paper assesses the impact of blogs on the download of papers. This again shows how being featured on a high traffic blog has an impact.

Video of Foundation Seminar

There is a video of my "foundation seminar" now available here. Slides are available here.

1. Energy Use Per Capita Increases Over Time

This is the first of my posts on "Energy and Growth: The Stylized Facts". There is nothing definitive about these facts and eventually I might adopt a different set. Astrid Kander picked seven facts which only partially overlap with mine.

The first fact is true globally:



and within individual countries:



In Sweden per capita energy use has been stable, in fact, for the last few decades, but there is no sign of an environmental Kuznets curve type relationship where energy use per capita falls at high income levels. Of course, energy use might be falling in countries suffering falling income. So this fact might be better combined with the second one (energy use per capita is higher in richer countries) as; "Energy use per capita rises with income per capita both within and across countries". As we see in Sweden the rate of growth of energy use is probably also dependent on the rate of growth of the economy. In slower growing countries improvements in energy intensity might just balance the "scale effect". This isn't so surprising as we see the same thing for carbon and maybe sulfur.

But I stated this fact in terms of time because the assumption of standard growth models that innovation is continuous over time and, therefore, so is economic growth.

ARC Grant

The Australian Research Council announced Discovery and Linkage grants starting in 2012 today. My team: Astrid Kander, Jack Pezzey, Chunbo Ma, and myself got a grant for our project: Energy transitions: past, present, and future. As is often the case we got much less money than we asked for - about a third. But I had applied for a DORA fellowship which I didn't get so we should be able to do most of what we planned with the money we got with some ingenuity. I'll post some more on our plans when I have more details. Congratulations also to Crawford School colleagues Michael Ward and Quentin Grafton who also got a grant to look at adaptive management of Australia's urban water; to Adrian Kay for: "The making and unmaking of Australian public policy: using Historical Institutionalism theory to understand the path from Medibank to Medicare": and Sango Mahanty for "Project Title: The political ecology of forest carbon: mainland Southeast Asia's new commodity frontier?".

Congratulations also to colleagues at the Research School of Economics John Stachurski and Renée Fry who also got grants. And at the Research School of Social Sciences, Simon Niemeyer. Well there are a lot more ANU people who got grants, these are just a few who I know.

From our Vice-Chancellor:

"ANU scholars won over 10 per cent of all funding.

102 projects from disciplines across the campus won a total of $34 million from a total pool of $310 million.

I particularly note that this year we have built on our traditionally high success rates with a very impressive 37 per cent of ANU applications under the Discovery Projects scheme awarded funding. This will see 90 projects begin in 2012, supported by $31.5 million.

This sets ANU at the top of the national scale for Discovery Project earnings."

Note that ANU is much smaller than most other Go8 universities and that the average success rate of Discovery proposals is just over 20%.

P.S. I've labelled this post with a new category "DP12". All posts about research resulting from this grant will be also labelled DP12.