Social capital as a network measure provides new insights on economic growth

Jaime Oliver Huidobro; Alberto Antonioni; Francesca Lipari; Ignacio Tamarit

doi:10.1371/journal.pone.0273066

Peer Review History

Original SubmissionMarch 11, 2022
11 May 2022 Decision Letter - Hocine Cherifi, Editor PONE-D-22-07302Social capital as a network measure provides new insights on economic growthPLOS ONE Dear Dr. Oliver Huidobro, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Jun 15 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. 5. We note that the grant information you provided in the ‘Funding Information’ and ‘Financial Disclosure’ sections do not match. When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for your study in the ‘Funding Information’ section. 6. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: No Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: No Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Thank you to the authors for this interesting paper examining network drivers of economic growth. 1. The authors are testing how economic connectivity (a la trade and migration networks) affects economic growth, which is a thoughtful and interesting hypothesis. Their measures seem plausibly related to growth (although as I mention below, I believe they are measuring economic connectivity, not social capital, which should be corrected before publication). 2. The authors measure economic connectivity/centrality in an economic network of OECD countries using financial trade flow data. They call these centrality measures 'social capital' - which is most certainly is not. Social capital refers to grassroots level ties that connect people, fostering trust and reciprocity (eg. Putnam, Coleman, Lin, any of the core literature on social capital). However, the authors have not measured social capital; they have measured economic connectivity, or perhaps economic centrality among countries. While deserving of inquiry, this paper does not actually test hypotheses about social capital but rather national level economic networks, and should be retitled and adapted accordingly. 3. It's a very sophisticated study, but I'm having a little trouble seeing the value added right now. We would naturally expect countries with more GDP probably end up making more (1) outward foreign direct investment elsewhere, because they have the money to do so. Countries with greater GDP (dependent variable) will also see more (2) inward trade and more (3) in-migration. These are basically three mutual proxies for the same concept, so it's a little unclear what the puzzle is here. Put more positively, could the authors please justify more clearly what gap this research is trying to address? 4. Their modeling strategy needs to address the inter-dependence of observations problem which occurs when using network centrality as a predictor/outcome (in this case, as predictors). Their observations' residuals will be correlated (heteroskedasticity) because the country-year observations are literally connected to one another (inter-dependent observations); they will often share similar predictor values. Heteroskedasticity compromises the validity of beta coefficient standard errors. There are a few solutions for this. The authors could (a) permute the networks themselves to calculate the median expected centrality at random, and then subtract that from the original centrality measure. This would give you a residual centrality measure that is corrected for network structure, and could be appropriately regressed as-is. This is admittedly kind of tricky and requires some coding, so I might suggest instead you try an alternative: (b) use statistical simulation (eg. CLARIFY in Stata, Zelig in R, etc.) to simulate the effects of your key independent variables on expected change in log GDP from a multivariate normal distribution. This uses your model equation as is, but does not rely on beta coefficients' standard errors, and so is robust to heteroskedasticity. This might be the easiest move here. Minor notes: 5. I am not personally an expert in elastic-net regression or gradient boosting models, and so cannot comment on these methods. I will just say that a simpler, more robust way to hypothesis test given correlated predictors would be to just use predicted values/statistical simulations as discussed above, since correlated predictors and heteroskedasticity only affect beta coefficients' standard errors, not model predictions. 6. Table 2 and later figures are difficult to read, because the authors have chosen to label their predictors using Greek letters, leaving readers to flip back and forth just to read the table. Please sub in simple English labels! 7. The authors appear to have linked raw data sources for a few of their variables, but it looks like PLOS ONE wants authors to share or embargo their entire replication code/data. FYI. Thank you for the opportunity to review this research. An exciting application of international trade and migration networks! Reviewer #2: The document is clear, well written, and the topic is relevant and current. At the same time, the approach and techniques used for the analysis are pertinent and relatively new to the economics discipline. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. Attachments Attachment Submitted filename: Review Report_Social capital as a network measure provides new insights on economic growth.pdf https://doi.org/10.1371/journal.pone.0273066.r001
Revision 1
7 Jul 2022 Author Response ### ------------------ ### Reviewer 1 ### ------------------ ### Thank you to the authors for this interesting paper examining network drivers of economic growth. -------------- Comment 1: The authors are testing how economic connectivity (a la trade and migration networks) affects economic growth, which is a thoughtful and interesting hypothesis. Their measures seem plausibly related to growth (although as I mention below, I believe they are measuring economic connectivity, not social capital, which should be corrected before publication). Answer: Thank you for the comment. We included a clarification in the draft in lines 72-79. As its mentioned in (Jackson 2019), social capital was defined by Pierre Bourdieu as (Bourdieu 1986) “the aggregate of the actual or potential resources which are linked to possession of a durable network of more or less institutionalized relationships of mutual acquaintance or recognition...”. This definition revolves around interactions among parties, not around individual properties. -------------- Comment 2: The authors measure economic connectivity/centrality in an economic network of OECD countries using financial trade flow data. They call these centrality measures 'social capital' - which is most certainly is not. Social capital refers to grassroots level ties that connect people, fostering trust and reciprocity (eg. Putnam, Coleman, Lin, any of the core literature on social capital). However, the authors have not measured social capital; they have measured economic connectivity, or perhaps economic centrality among countries. While deserving of inquiry, this paper does not actually test hypotheses about social capital but rather national level economic networks, and should be retitled and adapted accordingly. Answer: Thank you again for your comment. In this work we consider that economic transactions and migratory flows are a channel for information exchange. And as explained in lines 25-34, one of the drivers of TFP is the exchange of information through economic exchanges. The focus of the work is not total imports and exports (economic connectivity), but rather the share of monetary and migratory flows (We clarified this matter in lines 104-107). The main point is that diversification and positioning in the global networks provides access to information that is fundamental for innovation and, in turn, for productivity. This positioning in the network is what we identify as social capital. And using network centrality measures allows us to capture complex measures of diversification. The functional perspective (i.e. information access) of social capital is embedded in the structural perspective. Therefore we are interested in the structural properties of the networks and the role of countries in them. -------------- Comment 3: It's a very sophisticated study, but I'm having a little trouble seeing the value added right now. We would naturally expect countries with more GDP probably end up making more (1) outward foreign direct investment elsewhere, because they have the money to do so. Countries with greater GDP (dependent variable) will also see more (2) inward trade and more (3) in-migration. These are basically three mutual proxies for the same concept, so it's a little unclear what the puzzle is here. Put more positively, could the authors please justify more clearly what gap this research is trying to address? Answer: Thanks for the comment. The value added of the paper can be summarized in equation 5, where we propose that part of TFP can be explained as the social capital of countries in their network structure expression. We clarify this matter in lines 91-94 Our belief is that the mentioned concerns are already covered since: We are not using total imports/exports or total migration, but rather share (expressed as a percentage) by country. It's not about how much you export locally, but the centrality as a global network measure. We clarified this further in lines 104-107. Moreover, as the reviewer points out, it's true that the causal effect could be the other way around; more GDP could imply more economic and migratory centrality. However, we have already addressed this issue in the robustness check in line 327 with the AB estimates. -------------- Comment 4: Their modeling strategy needs to address the inter-dependence of observations problem which occurs when using network centrality as a predictor/outcome (in this case, as predictors). Their observations' residuals will be correlated (heteroskedasticity) because the country-year observations are literally connected to one another (inter-dependent observations); They will often share similar predictor values. Heteroskedasticity compromises the validity of beta coefficient standard errors. There are a few solutions for this. The authors could (a) permute the networks themselves to calculate the median expected centrality at random, and then subtract that from the original centrality measure. This would give you a residual centrality measure that is corrected for network structure, and could be appropriately regressed as-is. This is admittedly kind of tricky and requires some coding, so I might suggest instead you try an alternative (b) use statistical simulation (eg. CLARIFY in Stata, Zelig in R, etc.) to simulate the effects of your key independent variables on expected change in log GDP from a multivariate normal distribution. This uses your model equation as is, but does not rely on beta coefficients' standard errors, and so is robust to heteroskedasticity. This might be the easiest move here Answer: Thank you for the comment that helped us to clarify this concern. We explicitly use Heteroskedastic Autocorrelated Consistent (HAC) standard errors in our estimates, in order to avoid such issues. We clarified this in lines 229-233. Moreover, we have added an additional figure to the appendix showing that errors are homoscedastic across countries. I am not personally an expert in elastic-net regression or gradient boosting models, and so cannot comment on these methods. I will just say that a simpler, more robust way to hypothesis test given correlated predictors would be to just use predicted values/statistical simulations as discussed above, since correlated predictors and heteroskedasticity only affect beta coefficients' standard errors, not model predictions. Answer: Thank you again for the comment. We have included a robustness check section for multicollinearity issues. Elastic Net solves this issue, so we have added 2 more references as well as clarified the explanation of this matter in lines 311-313. About statistical simulations for standard errors, we show bootstrapped standard errors for the elastic net coefficient estimates in Fig 4. -------------- Comment 5: Table 2 and later figures are difficult to read, because the authors have chosen to label their predictors using Greek letters, leaving readers to flip back and forth just to read the table. Please sub in simple English labels! Answer: Thank you for the comment. We changed the labels in the tables to make them more readable. -------------- Comment 6: The authors appear to have linked raw data sources for a few of their variables, but it looks like PLOS ONE wants authors to share or embargo their entire replication code/data. FYI. Answer: Thanks for your comment, we will follow all guidelines required by the journal. ### ------------------ ### Reviewer 2 ### ------------------ ### The document is clear, well written, and the topic is relevant and current. At the same time, the approach and techniques used for the analysis are pertinent and relatively new to the economics discipline. Answer: Thank you for the revision and the support. ### ------------------ ### Journal Comments ### ------------------ ### -------------- Comment 1: When submitting your revision, we need you to address these additional requirements. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. Please update your submission to use the PLOS LaTeX template. Answer: Thank you for the feedback. We used the Latex template from Plos One’s website. We will upload all the files to reproduce the manuscript. -------------- Comment 2: We note that Figure S1 in your submission contain map images which may be copyrighted. All PLOS content is published under the Creative Commons Attribution License (CC BY 4.0), which means that the manuscript, images, and Supporting Information files will be freely available online, and any third party is permitted to access, download, copy, distribute, and use these materials in any way, even commercially, with proper attribution. For these reasons, we cannot publish previously copyrighted maps or satellite images created using proprietary data, such as Google software (Google Maps, Street View, and Earth). Answer: Thank you again for the comment. All figures were created by the authors with the specific purpose of this project. They are all therefore free of copyright. -------------- Comment 3: Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Answer: Thank you again for the feedback. We added captions to the figures and updated the citations accordingly, including the new figure in the Supporting information file. -------------- Comment 4: We note that the grant information you provided in the ‘Funding Information’ and ‘Financial Disclosure’ sections do not match. When you resubmit, please ensure that you provide the correct grant numbers for the awards you received for your study in the ‘Funding Information’ section. Answer: Thank you for pointing out the inconsistencies in the submission. Attachments Attachment Submitted filename: Rebuttal letter.pdf https://doi.org/10.1371/journal.pone.0273066.r002
3 Aug 2022 Decision Letter - Hocine Cherifi, Editor Social capital as a network measure provides new insights on economic growth PONE-D-22-07302R1 Dear Dr. Oliver Huidobro, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Hocine Cherifi Academic Editor PLOS ONE Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #2: (No Response) ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #2: (No Response) ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #2: (No Response) ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #2: (No Response) ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #2: (No Response) ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #2: No ******** https://doi.org/10.1371/journal.pone.0273066.r003
Formally Accepted
16 Aug 2022 Acceptance Letter - Hocine Cherifi, Editor PONE-D-22-07302R1 Social capital as a network measure provides new insights on economic growth Dear Dr. Oliver Huidobro : I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Professor Hocine Cherifi Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0273066.r004

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