visualization on Ray Yang, Ph.D.

Tracking the Change of Industry Positioning Caused by an Acquisition

Sun, 19 Apr 2020 00:00:00 +0000

1. Motivation

Due to enduring resource heterogeneity, firms tend to hold persistent positionings within an established industry (like commercial banking). However, transformative corporate actions may alter a firm’s asset structure and create a new industry for the acquirer. Thus, we can map out the industry positions and track the position change caused by an acquisition.

2. Mapping the Positioning and Tracking the Movement

2.1 the Biplot

Consider commercial banks as an example. Different banks may hold differently structured financial asset portfolios and occupy different positions. We can assess a bank’s position based on the proportion of cash, commercial loans, mortgage loans, etc., as a percentage in the total asset (i.e., multiple dimensions). A biplot can provide us a quick intuition about how those dimensions relate to one another. However, the relative positions shown on biplot would not be accurate due to the loss of information in dimension reduction.

2.2 the 3-D and 2-D Scatterplots based on MDS

In an alternative approach, we can build distance-based features by exploring the inter-firm distance using multi-dimensional scaling (MDS). On Feb. 12th, 2018, Pacific Premier Bancorp launched an acquisition of Grandpoint Capital. Using this acquisition event as an example, we can first calculate the interfirm distance using MDS and then track how the acquisition shifts a bank’s position (in both a 3-D and 2-D scatter plots).

the Positionings of Big Tech Firms on Industry Presence and Competition Description

Thu, 16 Apr 2020 00:00:00 +0000

In this post, I calculated the positioning of big tech firms based on two metrics, the multiple-industry presence (based on 3-digit SIC codes) versus the competition description (in 10-K filings), and compared the difference between the two approaches.

1 the positioning by industry presence across SIC categories

Scholars have used SIC codes to understand interfirm differences ¹ Big public firms typically straddle across multiple SIC industry categories. So it is straightforward and easy to see their positionings by multiple-industry participation. Accordingly, a firm’s position can be calculated as the sales distribution across multiple SIC industry categories ².

2 the positioning by competition description in 10-K filing

The SIC-code might be “backward-looking,” as firms tend to quite if particular combinations of multiple-industry business lines create economic inefficiencies. Only efficient multi-industry presence survives.

In contrast, the SEC filings may reflect managers’ current understanding of what they do. Especially when they characterize their competition, managers tend to draw their forward-looking expectations on the various forms of competitive threats. Some scholars³ and companies⁴ have used the text-based approach to calculate inter-industry distance.

2.1 calculating positioning based on the competition description

I collected the competition description texts of the largest 17 tech companies. Below are some frequently used words in those statements.

I ran an LDA topic modeling with 11 latent topics, which yields a low perplexity score.

The figure below shows how the 11 topics distribute across terms.

This is the topic loading on the 11 firms’ competition description, which is used to calculate the pairwise distance.

2.2 the final result: positioning by competition description

Here is the positioning map based on the competition description. The graph on the right shows the positioning of American companies. Looking at the results, we can see some interesting differences. The competition description moves some firms closer or further away from one another as compared to the SIC-presence positioning map.

for example:
Teece, D. J., Rumelt, R., Dosi, G., & Winter, S. (1994). Understanding corporate coherence: Theory and evidence. Journal of economic behavior & organization, 23(1), 1-30.

Lien, L. B., & Klein, P. G. (2013). Can the survivor principle survive diversification?. Organization Science, 24(5), 1478-1494.
↩
Litov, L. P., Moreton, P., & Zenger, T. R. (2012). Corporate strategy, analyst coverage, and the uniqueness paradox. Management Science, 58(10), 1797-1815.Lien, L. B., & Klein, P. G. (2013).↩
https://hobergphillips.tuck.dartmouth.edu ↩
Morningstart’s Company Comparables System ↩

Mapping Twitter Topics and Sentiment about FAAMG Companies since Covid-19 Outbreak

Wed, 15 Apr 2020 00:00:00 +0000

1 Motivation

On a whim, I mapped out what people say (the text) and feel (the sentiment) about the top tech companies (FAAMG) on twitter since the Covid-19 outbreak. The keywords and sentiment that are associated with the main topics should differ across these companies.

By no means I am drawing any causal association here. But the story starts with checking the recent price movements of the FAAMG stocks. Obviously, Covid-19 has impacted these companies quite differently.

2 Procedures

2.1 Data Source

For each company, I downloaded 1,000 tweets containing the company name as the hashtag (e.g. “#amazon” for Amazon). I used Python module “tweepy” to stream the data and set the “since” parameter to ‘2020-03-01’, which collects a sample of 1,000 tweets since March 1st.

2.2 Topic Modeling

Using Python module “gensim”, I detected three most significant topics (including Covid-19, business, and daily life), which are named by the associated keywords (most relevant terms).

Using Python module “vaderSentiment”, I computed sentiment scores for each tweet and aggregated the scores by company. The topic-based sentiment scores are used to construct the perceptual map, in which each company takes a different position. Using Python module “nltk”, I find the most frequent topic-based co-occurring words for each company.

3 Results

3.1 Perceptual Map of FAAMG Based on Topic Sentiment

It looks Amazon does well on all topics, especially on Covid-19-related topic. Microsoft and Apple do well on “Business”.

3.2 Keywords Co-occurrence Network on Each Topic

Here are the work keywords co-occurrence patterns for each topic of these companies.

“MMeM”: Modeling the Multivariate Mixed-effects

Sun, 10 Mar 2019 00:00:00 +0000

I co-developed an R pakcage “MMeM” for estimating the variance-covariance matrix of random effects \(\mathbf{u}\) and \(\mathbf{e}\) on multiple dependent variables.

Statistical Intuition

The univariate mixed-effects model

In univariate mixed-effects model: \(\mathbf{y} = \mathbf{Xb} + \mathbf{Zu} + \mathbf{e}\) (1), we estimate the variance component \(\sigma_u^2\) and \(\sigma_e^2\) for \(\mathbf{u} \sim N(\mathbf{0}, \sigma_u^2\mathbf{I})\) and \(\mathbf{e} \sim N(\mathbf{0}, \sigma_e^2\mathbf{I})\).

In formula (1): \(\mathbf{y}\) is n \(\times\) 1 response vector; \(\mathbf{X}\) and \(\mathbf{Z}\) are n \(\times\) p and n \(\times\) s; \(\mathbf{b}\) is p \(\times\) 1 coefficients vector for the fixed effects; \(\mathbf{u}\) is s \(\times\) 1 matrix for the random effects, \(\mathbf{e}\) is n \(\times\) 1 vector of random errors.

The multivariate mixed-effects model

In multivariate mixed-effects model: \(\mathbf{y} = (\mathbf{I} \otimes \mathbf{X})\mathbf{b} + (\mathbf{I} \otimes \mathbf{Z} )\mathbf{u} + \mathbf{e}\) (2), in which \(\mathbf{y} = \left\{\mathbf{y}_i\right\}_c, \mathbf{b} = \left\{\mathbf{b}_i\right\}_c, \mathbf{u} = \left\{\mathbf{u}_i\right\}_c, \mathbf{e} = \left\{\mathbf{e}_i\right\}_c, i =1, \dots, q\), we estimate the variance-covariance matrix of random effects \(\mathbf{u}\) and \(\mathbf{e}\) on \(q\) response variates, namely \(\mathbf{T}\) and \(\mathbf{E}\), for \(var(\mathbf{u}) = \mathbf{G} = \mathbf{T}\otimes \mathbf{I}_s, var(\mathbf{e}) = \mathbf{R} = \mathbf{E} \otimes \mathbf{I}_n, var(\mathbf{y}) = \mathbf{V} = \mathbf{T}\otimes \mathbf{ZZ}' + \mathbf{E} \otimes \mathbf{I}_n\).

In formula (2): \(\mathbf{y}\) is nq \(\times\) 1 response vector; \(\mathbf{X}\) is n \(\times\) p design matrix for the fixed effects; \(\mathbf{b}\) is pq \(\times\) 1 coefficients vector for the fixed effects; \(\mathbf{Z}\) is n \(\times\) s design matrix for the random effects; \(\mathbf{u}\) is sq \(\times\) 1 vector of the random effects; \(\mathbf{e}\) is nq \(\times\) 1 vector of random errors.

An Implementation Example

# install.packages("MMeM")
library(MMeM)
data(simdata)

Initialization

# initialize with a positive-definiate var-cov
T.start = matrix(c(10, 5, 5, 15), 2, 2)
E.start = matrix(c(10, 1, 1, 3), 2, 2)

Estimation

# using the Henderson3 estimation mothod
results_henderson = MMeM_henderson3(fml = c(V1,V2) ~ X_vec + (1|Z_vec), data = simdata, factor_X = TRUE)

## Bivariate response: V1 and V2

print(results_henderson)

## $T.estimates
##                 T: V1   T: V1 V2     T: V2
## T.estimates  65.47395   9.969188  9.766204
## T.variance  807.56303 128.824836 20.552160
## 
## $E.estimates
##                E: V1  E: V1 V2     E: V2
## E.estimates 55.74506 11.477502 41.171927
## E.variance  11.09826  8.196899  6.054027

“regrrr”: One-stop R-toolkit for Compiling Regression Results

Wed, 06 Mar 2019 00:00:00 +0000

In strategy/management research, we always need to compile the regression results into the publishable format and sometimes plot the moderating effects. Thus, I developed this “regrrr” package to help do the job.

Here is the quickstart guide.

Installation

To install from CRAN:

install.packages("regrrr")
library(regrrr)

You can also use devtools to install the latest development version:

devtools::install_github("raykyang/regrrr")
library(regrrr)

Examples

compile the correlation table

library(regrrr)

## Registered S3 methods overwritten by 'tibble':
##   method     from  
##   format.tbl pillar
##   print.tbl  pillar

data(mtcars)
m0 <- lm(mpg ~ vs + carb + hp + wt, data = mtcars)
m1 <- update(m0, . ~ . + wt * hp)
m2 <- update(m1, . ~ . + wt * vs)
cor.table(data = m2$model)

##          Mean  S.D.     1     2    3    4    5
## 1.mpg   20.09  6.03  1.00                     
## 2.vs     0.44  0.50  0.66  1.00               
## 3.carb   2.81  1.62 -0.55 -0.57 1.00          
## 4.hp   146.69 68.56 -0.78 -0.72 0.75 1.00     
## 5.wt     3.22  0.98 -0.87 -0.55 0.43 0.66 1.00

compile the regression table

regression_table <- rbind(
combine_long_tab(to_long_tab(summary(m0)$coef),
                 to_long_tab(summary(m1)$coef),
                 to_long_tab(summary(m2)$coef)),
compare_models(m0, m1, m2))
rownames(regression_table) <- NULL
print(regression_table)

##        Variables   Model 0   Model 1   Model 2
## 1    (Intercept) 35.435*** 48.157*** 46.698***
## 2                  (2.503)   (4.097)   (9.272)
## 3             vs     1.353     1.077     2.171
## 4                  (1.382)   (1.152)   (6.320)
## 5           carb    -0.057    -0.043    -0.009
## 6                  (0.449)   (0.374)   (0.426)
## 7             hp   -0.024† -0.113***   -0.107*
## 8                  (0.014)   (0.027)   (0.044)
## 9             wt -3.792*** -8.071***   -7.594*
## 10                 (0.658)   (1.307)   (3.016)
## 11         hp:wt             0.027**    0.025†
## 12                           (0.008)   (0.015)
## 13         vs:wt                        -0.367
## 14                                     (2.081)
## 15     R_squared     0.833     0.889     0.889
## 16 Adj_R_squared     0.808     0.867     0.862
## 17       Delta_F            12.517**     0.031

plot the moderating effect

plot_effect(reg.coef = summary(m2)$coefficients, data = mtcars, model = m2,
            x_var.name = "wt", y_var.name = "mpg", moderator.name = "hp",
            confidence_interval = TRUE,  CI_Ribbon = FALSE, 
            xlab = "Weight", ylab = "MPG", moderator.lab = "Horsepower") +
ggplot2::theme(text=ggplot2::element_text(family="Times New Roman", size = 16))

plot the moderating effect with a linear spline

library(lspline)
data(mtcars)
m3 <- lm(mpg ~ vs + carb + hp + lspline(wt, knots = 4, marginal = FALSE) * hp, data = mtcars)
plot_effect(reg.coef=summary(m3)$coefficients, data = mtcars, model = m3, 
            x_var.name = "wt", y_var.name = "mpg", moderator.name = "hp",
            xlab="Weight", ylab="MPG", moderator.lab="Horsepower") +
ggplot2::theme(text=ggplot2::element_text(family="Times New Roman", size = 16))

As we can see from the last line of code, the plot is customizable using “ggplot2”. There are a couple of other functions. Please see the reference manual on R documentation for details.

I’m also aiming to expand the package’s usage around its core functions. If you have any ideas or want to report a bug, please contact me or suggest on the GitHub page.

A Quick Bibliometric Analysis on “Positioning”

Tue, 26 Feb 2019 00:00:00 +0000

I had a whim and wanted to do some quick bibliometric analysis on the topic of “strategic positioning”.

The raw data is extracted from Web of Science. The search parameters:

TITLE: ("strategic positioning" OR "industry positioning" OR "market positioning")
Refined by: WEB OF SCIENCE CATEGORIES: ( MANAGEMENT OR BUSINESS OR ECONOMICS ) AND WEB OF SCIENCE CATEGORIES: ( MANAGEMENT OR BUSINESS OR INTERNATIONAL RELATIONS OR ECONOMICS ) AND DOCUMENT TYPES: ( ARTICLE ) AND LANGUAGES: ( ENGLISH )
Timespan: All years. 
Indexes: SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, BKCI-S, BKCI-SSH, ESCI, CCR-EXPANDED, IC.

I used the R package “bibliometrix” to conduct (1) “bibliographic coupling” and (2) “co-citation” analysis.

Bibliographic coupling analysis allows us to explore the “confluence and interactions” among recent papers. Two articles are bibliographically coupled if they co-cited at least one article.

Co-citation analysis allows us to trace back to the origin of thoughts and classic papers. Two articles have a co-citation tie if they are both cited in a third article.

Reference:

Aria, M. & Cuccurullo, C. (2017) bibliometrix: An R-tool for comprehensive science mapping analysis, Journal of Informetrics, 11(4), pp 959-975, Elsevier.