Showing posts with label Errata. Show all posts
Showing posts with label Errata. Show all posts

Wednesday, January 26, 2022

Typo in Directed Technical Change and the British Industrial Revolution

I hate reading my papers after they're published as there is usually some mistake somewhere. Unfortunately, I have to read them to do more research. I just found a typo in our 2021 paper in JAERE. Equation (8) should look like this:


In the published paper, there is a missing Gamma in the second term. 

I also noticed a couple of issues in the text of "Energy quality" published in Ecological Economics in 2010. One is in the introduction and is debatable: "Fuel and energy quality is not neccessarily fixed". This should be or instead of and or are instead of is. But it really isn't important. Then on p1475 we have "How does these measures". Again, not important.

Of course, the error in JAERE is not very important as the third term above is correct in the published paper.

Friday, November 24, 2017

Data and Code for "Energy and Economic Growth: The Stylized Facts" and an Erratum

Following a request for our estimation code we have now completed a full replication package for our 2016 Energy Journal paper and uploaded it to Figshare.

While we were putting this together we noticed some minor errors in the tables in the published paper. The reported standard errors of the coefficients of lnY/P in Tables 2 and 3 for the results without outliers are incorrect. We accidentally pasted the standard errors from Table 5 into Tables 2 and 3. The correct versions of Tables 2 and 3 should look like this:


The standard errors for unconditional convergence in Tables 4 and 6 are also incorrect. The reported standard errors are not robust and one was completely wrong. The tables should look like:


None of these errors results in the significance level in terms of 1%, 5% etc. changing.

Thursday, July 27, 2017

Error in 2014 Energy Journal Paper

I hate looking at my published papers because there are often typos in them which I didn't catch at the proofs stage...This time my coauthor, Stephan Bruns, found one in our 2014 paper in the Energy Journal: "Is There Really Granger Causality Between Energy Use and Output?" In Table 1, which describes the details of the studies in our meta-analysis, the control variable labeled "energy production" should actually be labeled "energy price". Energy production would be a weird control variable...

After digging into our draft files, it turns out I changed "energy pr." to "E Prod." systematically in this table just before we resubmitted it to the journal. I also added a footnote: "E Prod.=Energy Production". I don't know why I did this. I would have thought I would have asked, Christian Gross, who made the original version of the table, before doing this, but I can't find any email to prove that...

Friday, September 2, 2011

Erratum: Elasticities of substitution and complementarity, Journal of Productivity Analysis 36(1): 79-89

I hate looking at my published papers because there are often typos in them which I didn't catch at the proofs stage... One of our PhD students, Nitin Gupta, found a typo in my paper: Elasticities of substitution and complementarity, Journal of Productivity Analysis 36(1): 79-89. The formula in equation (20) for the Allen Elasticity of Substitution between inputs Xi and Xj, AESij, should be:



The denominator is wrong in the formula in the paper. The formula for AESii is correct. Note that these formulae only make sense if you have normalized the data in some way. If, for example, you have indexed all variables to one in the first year then the formula will give the elasticity in the first year. It makes the most sense when like me you have normalized on the sample mean for each variable and so this elasticity is at some notional mean point. If you want to calculate the elasticity at different points in time or you haven't normalized the data then you can't use this formula. This is because the parameters associated with the first order terms in the translog function depend on the units used.

The good news is that I used the correct formula in all the calculations in the paper. The bigger picture message is don't believe that a formula is correct just because it is printed in a refereed journal!