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[{"authors":null,"categories":null,"content":"Welcome to my research page. I am a data-driven social scientist that uses computational linguistics to examine entrepreneurial strategy decisions. Entrepreneurship is a cross-sectional discipline at its core, and my research perceives it at the intersection of strategy, marketing, and organizational sociology literature. Most recently, I have focused on how new ventures achieve optimal distinctiveness, i.e., how they handle the trade-off between simultaneously conforming to norms to appear legitimate and differentiating to appear novel and unique to realize competitive advantages. To handle this trade-off, I examine the role of cultural entrepreneurship, i.e., how entrepreneurs utilize cultural tools and elements, such as narratives or images, to convey information on their ventures and products. For empirical testing, I collect and analyze large-scale secondary data from publicly available online sources and process them with machine learning, such as image label recognition and natural language processing.\nSince 2023, I have been an Assistant Professor for Data Science and Entrepreneurship at Tilburg University and the Jheronimus Academy of Data Science. Before that, I held positions at the University of Siegen, RWTH Aachen University, and BI Business School in Oslo, Norway. My work appears in journals such as the Journal of Business Venturing, the International Journal of Innovation Management, and the Journal of Retailing. I also serve on the editorial review board of Entrepreneurship Theory \u0026amp; Practice.\n Download my resumé. -- ","date":1674691200,"expirydate":-62135596800,"kind":"term","lang":"en","lastmod":1674691200,"objectID":"2525497d367e79493fd32b198b28f040","permalink":"https://alexandervossen.github.io/author/alexander-vossen/","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/author/alexander-vossen/","section":"authors","summary":"Welcome to my research page. I am a data-driven social scientist that uses computational linguistics to examine entrepreneurial strategy decisions. Entrepreneurship is a cross-sectional discipline at its core, and my research perceives it at the intersection of strategy, marketing, and organizational sociology literature.","tags":null,"title":"Alexander Vossen","type":"authors"},{"authors":["Alexander Vossen"],"categories":["Staticstics","R"],"content":" It seems that nowadays, no paper on optimal distinctiveness gets published without a graph on how the s-shaped mechanisms of legitimacy loss and competitive gain result in a curvilinear effect. I collected some information from countless threads and guides and provided a small tutorial on how to do this in R. Here you go:\nFirst, we load the packages:\nlibrary(ggplot2) ## for plotting library(truncnorm) ## for making truncated normal distributions library(tikzDevice) ## for latex output library(patchwork) ## to group plots Then we create the logit function that helps us with the s-shapes.\n## generate logit function for s-shape f_logit \u0026lt;-function(b0,b1,b2,x) { 1/(1+exp((b0 +b1*x+b2*(x^2)))) } Then we generate some random data.\n## I like 1000 observations from 0 to 1 with mean 0.5 and sd 0.2 distinctiveness \u0026lt;- rtruncnorm(n=1000, a=0, b=1, mean=0.5, sd=0.2) df \u0026lt;- data.frame(distinctiveness) Moreover, compute some variables to plot. Note that I use the parameters proposed by Haans (2019).\n###generate s shapes for inverted u-shape df$competitive_gain \u0026lt;- f_logit(4,-12,0,df$distinctiveness) ## \u0026#34;stronger\u0026#34; df$legitimacy_loss \u0026lt;- f_logit(6,-10,0,df$distinctiveness) ## \u0026#34;weaker\u0026#34; df$inverted_u \u0026lt;-df$competitive_gain - df$legitimacy_loss ## substract from each other ####generate s shapes for u df$competitive_gain_u \u0026lt;- f_logit(6,-10,0,df$distinctiveness) ## \u0026#34;weaker\u0026#34; df$legitimacy_loss_u \u0026lt;- f_logit(4,-12,0,df$distinctiveness) ## \u0026#34;stronger\u0026#34; df$u \u0026lt;-df$competitive_gain_u - df$legitimacy_loss_u Now we can start to plot.\np1\u0026lt;- ggplot() + geom_line(data=df,aes(y = competitive_gain, x=distinctiveness, colour=\u0026#34;benefits\u0026#34;)) + geom_line(data=df,aes(y = legitimacy_loss, x=distinctiveness, colour=\u0026#34;costs\u0026#34;)) + scale_color_manual(name = \u0026#34;\u0026#34;, values = c( \u0026#34;benefits\u0026#34; = \u0026#34;darkgreen\u0026#34;, \u0026#34;costs\u0026#34; = \u0026#34;darkred\u0026#34;))+ labs(y=\u0026#34;Relative strength\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + theme_bw()+ theme(legend.position = c(0.8,0.3)) p2 \u0026lt;- ggplot() + geom_line(data=df,aes(y = inverted_u, x=distinctiveness)) + labs(y=\u0026#34;Performance\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + theme_bw() p3 \u0026lt;- ggplot() + geom_line(data=df,aes(y = competitive_gain_u, x=distinctiveness, colour=\u0026#34;benefits\u0026#34;)) + geom_line(data=df,aes(y = legitimacy_loss_u, x=distinctiveness, colour=\u0026#34;costs\u0026#34;)) + scale_color_manual(name = \u0026#34;\u0026#34;, values = c( \u0026#34;benefits\u0026#34; = \u0026#34;darkgreen\u0026#34;, \u0026#34;costs\u0026#34; = \u0026#34;darkred\u0026#34;))+ labs(y=\u0026#34;Relative strength\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + theme_bw()+ theme(legend.position = c(0.8,0.3)) p4 \u0026lt;- ggplot() + geom_line(data=df,aes(y = u, x=distinctiveness)) + labs(y=\u0026#34;Performance\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + theme_bw() This renders us four plots that we can then join into an excellent panel with patchwork.\n###patchwork plots p1+p2+p3+p4 And if you want to, you can save it as a Latex file to import into your paper. The width and height are what I found to fit nicely in my Latex layout.\n## create tikz file by specifying your path tikz(file = \u0026#34;~/your/path/mech_plots.tex\u0026#34;, width = 6.7, height = 3.4) p1+p2+p3+p4+plot_layout(ncol = 2) ## gives you two columns-redundant in this case dev.off() If you want the OG Haans (2019) plots just specify the inverse-logit function and rerun the code. Note that I changed theme(legend.position) so that the labels do not overlap with the new plots.\nf_logit \u0026lt;-function(b0,b1,b2,x) { exp((b0 +b1*x+b2*(x^2)))/(1+exp((b0 +b1*x+b2*(x^2)))) } ###generate s shapes for u-shape parameters from Haans(2019) df$competitive_gain \u0026lt;- f_logit(4,-12,0,df$distinctiveness) df$legitimacy_loss \u0026lt;- f_logit(6,-10,0,df$distinctiveness) df$inverted_u \u0026lt;-df$competitive_gain - df$legitimacy_loss ####generate s shapes for inverted u df$competitive_gain_u \u0026lt;- f_logit(6,-10,0,df$distinctiveness) df$legitimacy_loss_u \u0026lt;- f_logit(4,-12,0,df$distinctiveness) df$u \u0026lt;-df$competitive_gain_u - df$legitimacy_loss_u p1\u0026lt;- ggplot() + geom_line(data=df,aes(y = competitive_gain, x=distinctiveness, colour=\u0026#34;benefits\u0026#34;)) + geom_line(data=df,aes(y = legitimacy_loss, x=distinctiveness, colour=\u0026#34;costs\u0026#34;)) + scale_color_manual(name = \u0026#34;\u0026#34;, values = c( \u0026#34;benefits\u0026#34; = \u0026#34;darkgreen\u0026#34;, \u0026#34;costs\u0026#34; = \u0026#34;darkred\u0026#34;))+ labs(y=\u0026#34;Relative strength\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + theme_bw()+ theme(legend.position = c(0.8,0.6)) p2 \u0026lt;- ggplot() + geom_line(data=df,aes(y = inverted_u, x=distinctiveness)) + labs(y=\u0026#34;Performance\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ scale_y_continuous(breaks = NULL) + scale_x_continuous(breaks = NULL) + theme_bw() p3 \u0026lt;- ggplot() + geom_line(data=df,aes(y = competitive_gain_u, x=distinctiveness, colour=\u0026#34;benefits\u0026#34;)) + geom_line(data=df,aes(y = legitimacy_loss_u, x=distinctiveness, colour=\u0026#34;costs\u0026#34;)) + scale_color_manual(name = \u0026#34;\u0026#34;, values = c( \u0026#34;benefits\u0026#34; = \u0026#34;darkgreen\u0026#34;, \u0026#34;costs\u0026#34; = \u0026#34;darkred\u0026#34;))+ labs(y=\u0026#34;Relative strength\u0026#34;, x=\u0026#34;Distinctiveness\u0026#34;)+ …","date":1674691200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1674691200,"objectID":"0099320678dd454d47dc23b7d1767c99","permalink":"https://alexandervossen.github.io/post/plotting-u-shapes/","publishdate":"2023-01-26T00:00:00Z","relpermalink":"/post/plotting-u-shapes/","section":"post","summary":"It seems that nowadays, no paper on optimal distinctiveness gets published without a graph on how the s-shaped mechanisms of legitimacy loss and competitive gain result in a curvilinear effect.","tags":["Statistics","Code"],"title":"Plotting (inverted) u-shapes in R","type":"post"},{"authors":["Alexander Vossen"],"categories":["publications"],"content":"New paper on Optimal Distinctiveness and organizational learning! I am happy to share our latest working paper on how content creators on YouTube learn from the feedback they get on their content releases. Check it out here.\n","date":1672617600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1672617600,"objectID":"16705aa42cedfd3d6c963b6749874ee1","permalink":"https://alexandervossen.github.io/post/2023-01-02-new-wp/","publishdate":"2023-01-02T00:00:00Z","relpermalink":"/post/2023-01-02-new-wp/","section":"post","summary":"New paper on Optimal Distinctiveness and organizational learning! I am happy to share our latest working paper on how content creators on YouTube learn from the feedback they get on their content releases.","tags":["Natural Language Processing","Learning","Failure"],"title":"New working paper - Reaching for the stars?","type":"post"},{"authors":["Stephanie Weiss","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1672617600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1672617600,"objectID":"f67b6151155f7ca120bd4c0e127ab3d9","permalink":"https://alexandervossen.github.io/publication/journal-article-reaching-stars/","publishdate":"2023-01-02T00:00:00Z","relpermalink":"/publication/journal-article-reaching-stars/","section":"publication","summary":"Analyzing how content creators on YouTube learn from past differentiation decisions.","tags":["Natural Language Processing","Learning","Failure"],"title":"Reaching for the stars? Entrepreneurial aspirations and optimal distinctiveness on YouTube","type":"publication"},{"authors":["Stephanie Weiss","Klemens Knoeferle","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1671494400,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1671494400,"objectID":"14fe7ea4110b5a4acd2c69998ca3bcf9","permalink":"https://alexandervossen.github.io/publication/journal-article-more-eye/","publishdate":"2022-12-20T00:00:00Z","relpermalink":"/publication/journal-article-more-eye/","section":"publication","summary":"Analyzing how new ventures convey information via product images.","tags":["Natural Language Processing","New ventures","Storytelling","Image label recognition"],"title":"More than meets the eye? Visual storytelling and optimal distinctiveness of new ventures in online B2C markets","type":"publication"},{"authors":["Alexander Vossen"],"categories":["publications"],"content":"New paper on Optimal Distinctiveness and visual storytelling! I am happy to share our latest working paper on how startups use product images in online b2c markets. Check it out here.\n","date":1671494400,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1671494400,"objectID":"bc3e3333ecf9effb65db22fa6693084a","permalink":"https://alexandervossen.github.io/post/2022-12-20-new-wp/","publishdate":"2022-12-20T00:00:00Z","relpermalink":"/post/2022-12-20-new-wp/","section":"post","summary":"New paper on Optimal Distinctiveness and visual storytelling! I am happy to share our latest working paper on how startups use product images in online b2c markets. Check it out here.","tags":["Natural Language Processing","New ventures","Storytelling","Image label recognition"],"title":"New working paper - More than meets the eye?","type":"post"},{"authors":["Stephanie Weiss","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1670889600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1670889600,"objectID":"2791fee65f13c610afaccd8a773b7c31","permalink":"https://alexandervossen.github.io/publication/journal-article-dancing-tunes/","publishdate":"2022-12-13T00:00:00Z","relpermalink":"/publication/journal-article-dancing-tunes/","section":"publication","summary":"Analyzing how campaigns win endorsement from both first-time and repeat backers.","tags":["Natural Language Processing","New ventures","Legitimacy"],"title":"Dancing to Multiple Tunes: Establishing Legitimacy with First-Time and Repeat Backers in Crowdfunding Campaigns","type":"publication"},{"authors":["Alexander Vossen"],"categories":["publications"],"content":"New paper on Optimal Distinctiveness \u0026amp; Cultural Entrepreneurship! I am happy to share our latest working paper on how crowdfunding campaigns build legitimacy with new and returning backers. Check it out here.\n","date":1670889600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1670889600,"objectID":"b4fbf45e896fab636cd58c80f5c4d8fc","permalink":"https://alexandervossen.github.io/post/2022-12-13-new-wp/","publishdate":"2022-12-13T00:00:00Z","relpermalink":"/post/2022-12-13-new-wp/","section":"post","summary":"New paper on Optimal Distinctiveness \u0026 Cultural Entrepreneurship! I am happy to share our latest working paper on how crowdfunding campaigns build legitimacy with new and returning backers. Check it out here.","tags":["Natural Language Processing","New ventures","Legitimacy"],"title":"New working paper - Dancing to multiple tunes","type":"post"},{"authors":["Stephanie Weiss","Klemens Knöferle","Alexander Vossen"],"categories":null,"content":"We examine how new ventures in online B2C marketplaces use visuals, such as product videos and images, in their strife for optimal distinctiveness, that is, being as different as conformingly possible. Building on research on cultural entrepreneurship as well as sensory marketing and perception, our work shows that visuals help new ventures orchestrate their distinct organizational identity, that is, appearing either more conforming or different to evaluating audiences than they truly are. We use machine learning approaches from image label recognition and natural language processing on videos and images of 1,157 entrepreneurial products offered on Amazon Launchpad to analyze the effect of the visual semantics—the meaning contained in visuals—on product performance. We find that visual semantics matter most for a new venture’s product performance when firm distinctiveness is low, albeit with a juxtaposing effect: While visuals should adhere to consumer expectations in terms of semantic fit, that is, the type of meaning they convey, they should deviate in terms of semantic richness, that is, the extent of meaning conveyed. By offering a multifaceted perceptual perspective on the way a distinct organizational identity is visually conveyed to audiences, our work has important implications for research on optimal distinctiveness. For managers, our work demonstrates clear guidelines for designing and using semantics in product videos and images to appear more or less unique to consumer audiences in online B2C marketplaces.\n Click on the Slides button above to view the built-in slides feature. Slides can be added in a few ways: - **Create** slides using Wowchemy\u0026#39;s [*Slides*](https://wowchemy.com/docs/managing-content/#create-slides) feature and link using `slides` parameter in the front matter of the talk file - **Upload** an existing slide deck to `static/` and link using `url_slides` parameter in the front matter of the talk file - **Embed** your slides (e.g. Google Slides) or presentation video on this page using [shortcodes](https://wowchemy.com/docs/writing-markdown-latex/). Further event details, including [page elements](https://wowchemy.com/docs/writing-markdown-latex/) such as image galleries, can be added to the body of this page. -- ","date":1659961800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1659961800,"objectID":"83752f19a940d980da11362d7389a2b6","permalink":"https://alexandervossen.github.io/talk/paper-session-at-aom-2022/","publishdate":"2022-08-08T12:30:00Z","relpermalink":"/talk/paper-session-at-aom-2022/","section":"event","summary":"Conference presentation on how NLP can be used for visual entrepreneurial storytelling.","tags":[],"title":"Paper Session at AOM 2022","type":"event"},{"authors":["Stephanie Weiss","Klemens Knöferle","Alexander Vossen"],"categories":null,"content":"We examine how new ventures in online B2C marketplaces use visuals, such as product videos and images, in their strife for optimal distinctiveness, that is, being as different as conformingly possible. Building on research on cultural entrepreneurship as well as sensory marketing and perception, our work shows that visuals help new ventures orchestrate their distinct organizational identity, that is, appearing either more conforming or different to evaluating audiences than they truly are. We use machine learning approaches from image label recognition and natural language processing on videos and images of 1,157 entrepreneurial products offered on Amazon Launchpad to analyze the effect of the visual semantics—the meaning contained in visuals—on product performance. We find that visual semantics matter most for a new venture’s product performance when firm distinctiveness is low, albeit with a juxtaposing effect: While visuals should adhere to consumer expectations in terms of semantic fit, that is, the type of meaning they convey, they should deviate in terms of semantic richness, that is, the extent of meaning conveyed. By offering a multifaceted perceptual perspective on the way a distinct organizational identity is visually conveyed to audiences, our work has important implications for research on optimal distinctiveness. For managers, our work demonstrates clear guidelines for designing and using semantics in product videos and images to appear more or less unique to consumer audiences in online B2C marketplaces.\n Click on the Slides button above to view the built-in slides feature. Slides can be added in a few ways: - **Create** slides using Wowchemy\u0026#39;s [*Slides*](https://wowchemy.com/docs/managing-content/#create-slides) feature and link using `slides` parameter in the front matter of the talk file - **Upload** an existing slide deck to `static/` and link using `url_slides` parameter in the front matter of the talk file - **Embed** your slides (e.g. Google Slides) or presentation video on this page using [shortcodes](https://wowchemy.com/docs/writing-markdown-latex/). Further event details, including [page elements](https://wowchemy.com/docs/writing-markdown-latex/) such as image galleries, can be added to the body of this page. -- ","date":1657355400,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1657355400,"objectID":"de158a0ec323baffae0afe228ddc9ddb","permalink":"https://alexandervossen.github.io/talk/paper-session-at-sase-2022/","publishdate":"2022-07-09T08:30:00Z","relpermalink":"/talk/paper-session-at-sase-2022/","section":"event","summary":"Conference presentation on how NLP can be used for visual entrepreneurial storytelling.","tags":[],"title":"Paper Session at Sase 2022","type":"event"},{"authors":["Jonas Janisch","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1652313600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1652313600,"objectID":"360b055f42154a7c9050177cbeb1c4c5","permalink":"https://alexandervossen.github.io/publication/journal-article-categorically-right/","publishdate":"2022-05-12T00:00:00Z","relpermalink":"/publication/journal-article-categorically-right/","section":"publication","summary":"Analyzing how the appeal of firm-level distinctiveness for new ventures varies across online consumer product categories.","tags":["Panel data","Secondary data"],"title":"Categorically Right? How Firm-Level Distinctiveness Affects Performance Across Product Categories","type":"publication"},{"authors":["Alexander Vossen"],"categories":["publications"],"content":"New paper on Optimal Distinctiveness! I am very excited to share that the first paper of my first PhD student Jonas has been accepted at the Journal of Business Venturing. I am very happy for him and looking forward to publishing the other papers of his thesis with him soon. For the next two weeks, you can follow the link and get a free copy of the paper here. Or check out the entry on my site here.\n","date":1652313600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1652313600,"objectID":"d8c32a57432fcc7f55f824b4b599ad01","permalink":"https://alexandervossen.github.io/post/2022-05-12-new-publication/","publishdate":"2022-05-12T00:00:00Z","relpermalink":"/post/2022-05-12-new-publication/","section":"post","summary":"New paper on Optimal Distinctiveness! I am very excited to share that the first paper of my first PhD student Jonas has been accepted at the Journal of Business Venturing. I am very happy for him and looking forward to publishing the other papers of his thesis with him soon.","tags":["panel data","new ventures"],"title":"New publication - Categorically right?","type":"post"},{"authors":["Alexander Vossen"],"categories":["Staticstics","R"],"content":" When dealing with panel data, one must expect biased standard errors. An excellent paper on this issue is Petersen (2009) which this post builds on. Most commonly, the bias results from either correlation between different time periods of a group (a group effect) or a correlation across different groups within the same time period (a time effect). While the former is often referred to as serial correlation, the latter is referred to as cross-sectional dependence.\nUsually, when you use a package such as plm you have two different options to choose from for both random effect and fixed effect models to account for the one, the other, or both: the individual (only the group effect), the time (only the time effect) or the twoways effect (both group and time effect). Although this seems easy right away, there may be situations where you cannot simply specify twoways effects (for example, if you intend to use the nested random effect model) or, more critically, in my opinion, one of the key assumptions of this approach is not valid: namely that both group and time effects are “fixed.”\n“Fixed” means that a group effect stays constant across all your time observations. This means implicitly that you assume that the impact of all the things you do not know or cannot measure for a firm is time-invariant, which is a strong assumption.\nThink about the following examples: Image you are interested in the money raised by start-ups in several funding rounds. It is well known that the pitch, i.e., the presentation, influences investors (Martens, Jennings, and Jennings 2007). The problem is that often you cannot explicitly measure how “good” the pitch was—you are usually not present and do not have a clear indication of how well investors received it.\nAs you have observations from multiple funding rounds, you usually would use a dummy for each start-up to control for such unobserved effects. However, that dummy does not change and stays the same across all funding rounds—even though a presenter’s performance at the respective pitches might vary enormously (think about either having a bad day or it may be even a completely different presenter in different funding rounds). Therefore, the “fixed” group dummy may be biased.\nFor the time effect, the situation is similar. For capturing time effects, you would use year dummies to indicate in which year the funding took place. Again this is “fixed”; in this case, this means that it is the same for all start-ups that looked for funding in a given year. Just think about the pandemic: How realistic is it that funding rounds in 2021 have been identical for a start-up that works on a covid vaccine and a start-up that works on a dating app (which no one can use in a lockdown)? These simplified examples show that such “fixed” time and group effects are a strong assumption.\nPetersen (2009) recommends an additional and possibly even superior way of addressing this issue: Clustering your standard errors for the time and group clusters. I used it for one of my projects, and I wanted to share a small function I wrote to quickly test if a group and/or time effect is present in your data. Let me illustrate with the \u0026#34;Fatalities\u0026#34; data that comes with the AER package.\nlibrary(plm) #for estimating models library(AER) #for data library(lmtest) #for coeftest command data(Fatalities) rdm \u0026lt;- plm(fatal ~ unemp+income+miles+beertax, index= c(\u0026#34;state\u0026#34;, \u0026#34;year\u0026#34;), model= \u0026#34;random\u0026#34;, effect= \u0026#34;twoways\u0026#34;, data=Fatalities) # run a random effect regression summary(rdm) ## Twoways effects Random Effect Model ## (Swamy-Arora\u0026#39;s transformation) ## ## Call: ## plm(formula = fatal ~ unemp + income + miles + beertax, data = Fatalities, ## effect = \u0026#34;twoways\u0026#34;, model = \u0026#34;random\u0026#34;, index = c(\u0026#34;state\u0026#34;, ## \u0026#34;year\u0026#34;)) ## ## Balanced Panel: n = 48, T = 7, N = 336 ## ## Effects: ## var std.dev share ## idiosyncratic 7081.10 84.15 0.009 ## individual 744674.57 862.95 0.990 ## time 376.31 19.40 0.001 ## theta: 0.9632 (id) 0.4693 (time) 0.4693 (total) ## ## Residuals: ## Min. 1st Qu. Median 3rd Qu. Max. ## -297.995 -45.673 -5.660 29.962 583.503 ## ## Coefficients: ## Estimate Std. Error z-value Pr(\u0026gt;|z|) ## (Intercept) 8.2922e+02 2.3080e+02 3.5928 0.0003271 *** ## unemp -2.3422e+01 5.4540e+00 -4.2944 1.752e-05 *** ## income 2.7880e-02 1.0932e-02 2.5503 0.0107624 * ## miles -6.0498e-04 4.8299e-03 -0.1253 0.9003188 ## beertax -2.1565e+02 8.6497e+01 -2.4931 0.0126639 * ## --- ## Signif. codes: 0 \u0026#39;***\u0026#39; 0.001 \u0026#39;**\u0026#39; 0.01 \u0026#39;*\u0026#39; 0.05 \u0026#39;.\u0026#39; 0.1 \u0026#39; \u0026#39; 1 ## ## Total Sum of Squares: 3134900 ## Residual Sum of Squares: 2492200 ## R-Squared: 0.205 ## Adj. R-Squared: 0.1954 ## Chisq: 85.3536 on 4 DF, p-value: \u0026lt; 2.22e-16 What we need to do now is to test the standard errors for bias. A good starting point for this is the coeftest function provided by the lmtest package. First, we compute so-called robust standard errors, where robust stands for heteroscedasticity robust. Usually this is done via a method developed by White (which is why you call it that way in the …","date":1650931200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1650931200,"objectID":"cff3df178c202c989baca4608ad7db9c","permalink":"https://alexandervossen.github.io/post/un-biasing-standard-errors-in-panel-data/","publishdate":"2022-04-26T00:00:00Z","relpermalink":"/post/un-biasing-standard-errors-in-panel-data/","section":"post","summary":"When dealing with panel data, one must expect biased standard errors. An excellent paper on this issue is Petersen (2009) which this post builds on. Most commonly, the bias results from either correlation between different time periods of a group (a group effect) or a correlation across different groups within the same time period (a time effect).","tags":["Statistics","Panel data","Standard errors","Code"],"title":"Un-biasing standard errors in panel data","type":"post"},{"authors":null,"categories":null,"content":"In this project, my co-authors and I focus on cultural entrepreneurship as a strategic resource. In particular, we intend to find out how new ventures and entrepreneurs alike can use texts or visuals to influence evaluating audiences, such as consumers or investors. A prime illustration for this idea is our 2020 paper in JBV, where we look at Indie Game Developers and how they try to narrate their game idea to potential buyers. Most recently, our work focusses on non-written narratives, such as visual or spoken ones. We will hopefully be able to share some working papers in the very near future.\n","date":1648425600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1648425600,"objectID":"6798fb8848c9724a1fa7212a2ea581de","permalink":"https://alexandervossen.github.io/project/cultural-entrepreneurship/","publishdate":"2022-03-28T00:00:00Z","relpermalink":"/project/cultural-entrepreneurship/","section":"project","summary":"Work that centers around using images, videos and narratives to tell stories about new ventures and their products.","tags":["Secondary data","Label recognition","Natural Language Processing"],"title":"Cultural Entrepreneurship","type":"project"},{"authors":null,"categories":null,"content":"In this project, my co-authors and I focus on how new ventures achieve optimal distinctiveness, i.e., how they become as unique as possible while still being perceived as a legitimate market actor. Much of our work in this project addresses audience evaluation and special category contexts. At the moment, we particularly focus on how optimal distinctiveness evolves over time and how it works in the context of international markets. We will upload these working papers as soon as they are ready. With some papers under review, we hope to be able to share some good news soon.\n","date":1648425600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1648425600,"objectID":"108d89684dca02b22a86bb3a03c835c4","permalink":"https://alexandervossen.github.io/project/optimal-distinctiveness/","publishdate":"2022-03-28T00:00:00Z","relpermalink":"/project/optimal-distinctiveness/","section":"project","summary":"Work on how new ventures should handle the trade-off between conforming and standing out.","tags":["Secondary data"],"title":"Optimal Distinctiveness","type":"project"},{"authors":[],"categories":null,"content":" Click on the Slides button above to view the built-in slides feature. Slides can be added in a few ways: - **Create** slides using Wowchemy\u0026#39;s [*Slides*](https://wowchemy.com/docs/managing-content/#create-slides) feature and link using `slides` parameter in the front matter of the talk file - **Upload** an existing slide deck to `static/` and link using `url_slides` parameter in the front matter of the talk file - **Embed** your slides (e.g. Google Slides) or presentation video on this page using [shortcodes](https://wowchemy.com/docs/writing-markdown-latex/). Further event details, including [page elements](https://wowchemy.com/docs/writing-markdown-latex/) such as image galleries, can be added to the body of this page. -- ","date":1646730000,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1646730000,"objectID":"aaf765578c157bca5a66521f7373e846","permalink":"https://alexandervossen.github.io/talk/symposium-on-entrepreneurial-strategy-at-vhb2022/","publishdate":"2017-01-01T00:00:00Z","relpermalink":"/talk/symposium-on-entrepreneurial-strategy-at-vhb2022/","section":"event","summary":"Invited talk where I spoke about new ventures and optimal distinctiveness.","tags":[],"title":"Symposium on Entrepreneurial Strategy at VHB2022","type":"event"},{"authors":["Christoph Ihl","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1619827200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1619827200,"objectID":"f732efd9e1bdd29267428738b4e8c1ec","permalink":"https://alexandervossen.github.io/publication/journal-article-paying-legitimacy/","publishdate":"2021-05-01T00:00:00Z","relpermalink":"/publication/journal-article-paying-legitimacy/","section":"publication","summary":"Experimental studies on how monetary rewards can make innovation contests hosted by firms more legitimate.","tags":["Legitimacy","Incentives"],"title":"Paying for Legitimacy? The Signalling Effect of Monetary Rewards in Innovation Contests","type":"publication"},{"authors":["Alexander Vossen"],"categories":["General"],"content":"New year, new conference season! My recent study with Stephie has been accepted at the SASE 2022 and the AOM 2022 Annual Conference! If you want to meet up in beautiful Amsterdam and/or Seattle make sure to drop me a mail!\n","date":1607817600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1648425600,"objectID":"342ad6e733ed0cd9ed8662c0355ec255","permalink":"https://alexandervossen.github.io/post/2022-03-28-conferences/","publishdate":"2020-12-13T00:00:00Z","relpermalink":"/post/2022-03-28-conferences/","section":"post","summary":"New year, new conference season! My recent study with Stephie has been accepted at the SASE 2022 and the AOM 2022 Annual Conference! If you want to meet up in beautiful Amsterdam and/or Seattle make sure to drop me a mail!","tags":["Academic"],"title":"New conference talks","type":"post"},{"authors":["Alexander Vossen"],"categories":["General"],"content":"New page launched! I am very happy that I have finally found the time to compile this new site that focuses on my work as a researcher. On it, you can find announcements for talks, teaching materials, papers, data, code and everything else that has to do with my work. Also, I will share some (hopefully) nifty tricks that I learned in my ten years as an empirical researcher that utilizes large-scale secondary data.\nEnjoy reading and browsing and feel free to drop me a mail in case you have any questions!\n","date":1607817600,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1648425600,"objectID":"84520760306abcc4313e2c2063eae971","permalink":"https://alexandervossen.github.io/post/2022-03-28-welcome/","publishdate":"2020-12-13T00:00:00Z","relpermalink":"/post/2022-03-28-welcome/","section":"post","summary":"New page launched! I am very happy that I have finally found the time to compile this new site that focuses on my work as a researcher. On it, you can find announcements for talks, teaching materials, papers, data, code and everything else that has to do with my work.","tags":["Academic"],"title":"Welcome to my page","type":"post"},{"authors":["Alexander Vossen","Christoph Ihl"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1598918400,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1598918400,"objectID":"940e756ff1d35bf8b5a24774fbc4a076","permalink":"https://alexandervossen.github.io/publication/journal-article-more-than-words/","publishdate":"2020-11-01T00:00:00Z","relpermalink":"/publication/journal-article-more-than-words/","section":"publication","summary":"Using natural language processing to analyze the way Indie Game Developers narrate their games to consumers.","tags":["Natural Language Processing","Secondary data"],"title":"More than words! How narrative anchoring and enrichment help to balance differentiation and conformity of entrepreneurial products","type":"publication"},{"authors":[],"categories":[],"content":"Create slides in Markdown with Wowchemy Wowchemy | Documentation\n Features Efficiently write slides in Markdown 3-in-1: Create, Present, and Publish your slides Supports speaker notes Mobile friendly slides Controls Next: Right Arrow or Space Previous: Left Arrow Start: Home Finish: End Overview: Esc Speaker notes: S Fullscreen: F Zoom: Alt + Click PDF Export: E Code Highlighting Inline code: variable\nCode block:\nporridge = \u0026#34;blueberry\u0026#34; if porridge == \u0026#34;blueberry\u0026#34;: print(\u0026#34;Eating...\u0026#34;) Math In-line math: $x + y = z$\nBlock math:\n$$ f\\left( x \\right) = ;\\frac{{2\\left( {x + 4} \\right)\\left( {x - 4} \\right)}}{{\\left( {x + 4} \\right)\\left( {x + 1} \\right)}} $$\n Fragments Make content appear incrementally\n{{% fragment %}} One {{% /fragment %}} {{% fragment %}} **Two** {{% /fragment %}} {{% fragment %}} Three {{% /fragment %}} Press Space to play!\nOne **Two** Three A fragment can accept two optional parameters:\n class: use a custom style (requires definition in custom CSS) weight: sets the order in which a fragment appears Speaker Notes Add speaker notes to your presentation\n{{% speaker_note %}} - Only the speaker can read these notes - Press `S` key to view {{% /speaker_note %}} Press the S key to view the speaker notes!\n Only the speaker can read these notes Press S key to view Themes black: Black background, white text, blue links (default) white: White background, black text, blue links league: Gray background, white text, blue links beige: Beige background, dark text, brown links sky: Blue background, thin dark text, blue links night: Black background, thick white text, orange links serif: Cappuccino background, gray text, brown links simple: White background, black text, blue links solarized: Cream-colored background, dark green text, blue links Custom Slide Customize the slide style and background\n{{\u0026lt; slide background-image=\u0026#34;/media/boards.jpg\u0026#34; \u0026gt;}} {{\u0026lt; slide background-color=\u0026#34;#0000FF\u0026#34; \u0026gt;}} {{\u0026lt; slide class=\u0026#34;my-style\u0026#34; \u0026gt;}} Custom CSS Example Let’s make headers navy colored.\nCreate assets/css/reveal_custom.css with:\n.reveal section h1, .reveal section h2, .reveal section h3 { color: navy; } Questions? Ask\nDocumentation\n","date":1549324800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1549324800,"objectID":"0e6de1a61aa83269ff13324f3167c1a9","permalink":"https://alexandervossen.github.io/slides/example/","publishdate":"2019-02-05T00:00:00Z","relpermalink":"/slides/example/","section":"slides","summary":"An introduction to using Wowchemy's Slides feature.","tags":[],"title":"Slides","type":"slides"},{"authors":["Christoph Ihl","Alexander Vossen","Frank Piller"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1548979200,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1548979200,"objectID":"e3251c9f4a4ef89ec9671806c96ee0c2","permalink":"https://alexandervossen.github.io/publication/journal-article-all-money/","publishdate":"2019-02-01T00:00:00Z","relpermalink":"/publication/journal-article-all-money/","section":"publication","summary":"Finding out how extrinsic and intrinsic motives translate into different types of particpation behavior in innovation contests.","tags":["Legitimacy","Incentives"],"title":"All for the Money? The Limits of Monetary Rewards in Innovation Contests with Users","type":"publication"},{"authors":["Klemens Knoeferle","Vilhelm Paus","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1512086400,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1512086400,"objectID":"e2cf61c8ccf0b6ff608dffa5212d5a00","permalink":"https://alexandervossen.github.io/publication/journal-article-upbeat/","publishdate":"2017-12-01T00:00:00Z","relpermalink":"/publication/journal-article-upbeat/","section":"publication","summary":"Field experiment on how music tempo and in-store crowding affects shopping behavior.","tags":["Visuals"],"title":"An Upbeat Crowd. Fast In-store Music Alleviates Negative Effects of High Social Density on Customers’ Spending","type":"publication"},{"authors":["Viktoria Boss","Robin Kleer","Alexander Vossen"],"categories":null,"content":" Click the Cite button above to demo the feature to enable visitors to import publication metadata into their reference management software. Create your slides in Markdown - click the Slides button to check out the example. Supplementary notes can be added here, including [code, math, and images](https://wowchemy.com/docs/writing-markdown-latex/). --- ","date":1491004800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":1491004800,"objectID":"4929fbd8743555016fc2626da64f1f47","permalink":"https://alexandervossen.github.io/publication/journal-article-walking/","publishdate":"2020-11-01T00:00:00Z","relpermalink":"/publication/journal-article-walking/","section":"publication","summary":"Lab experiment on how collaboration and competition affect particpants in innovation contests.","tags":["Collaboration","Incentives"],"title":"Walking Parallel Paths or Taking the Same Road? The Effect of Collaborative Incentives in Innovation Contests","type":"publication"},{"authors":null,"categories":null,"content":"","date":-62135596800,"expirydate":-62135596800,"kind":"page","lang":"en","lastmod":-62135596800,"objectID":"f26b5133c34eec1aa0a09390a36c2ade","permalink":"https://alexandervossen.github.io/admin/config.yml","publishdate":"0001-01-01T00:00:00Z","relpermalink":"/admin/config.yml","section":"","summary":"","tags":null,"title":"","type":"wowchemycms"}]