Institu

tfür

Soziologie,LMU

MarcKeuschnigg

TheBe

stsellerPh

enom

enon

Revisited

TheDiffusionof

Book

s

Whatm

akes

usbu

y:

Habits,adverts,o

rsocialcon

tagion

?

VIU,N

ov.30,2009

1/18

#2

30.11.2009

MarcKeuschnigg

Diffusionof

BooksCo

nten

tsDiffusionof

Books:Co

nten

ts

1Stateof

research

ondiffusionof

books

1Stateof

research

ondiffusionof

books

2Theo

ry:

2rather

basicand1integrated

mod

elof

diffusion

yg

ExternalInflu

ence

Mod

el

InternalInflu

ence

Mod

el

Mixed

Influ

ence

Mod

el

3Em

pirics:

Dobo

okcharacteristicsde

term

inethetype

ofdiffusion?

Twostep

approach,using

book

leveldata

Testforreliability:multilevelapp

roach,stillusingmacro

leveldata

Testforvalidity

:loo

king

atreaders,usingmicro

leveldata

#3

30.11.2009

MarcKeuschnigg

Stateof

Research

Stateof

Research

Curren

tstate

ofresearch

ondiffusionof

books

Ingene

ral,successfullhed

onicgood

s(e.g.m

ovies,musicalbu

ms,bo

oks)

exibithe

avyadop

tions

intheirearlylifecycles

anddiminishing

salesfurthe

ron

yp

yy

g(see

Clem

ente

tal.2006

foran

overview

).

Beck

(2007)

offersan

exem

plaryfit

ofan

elaboratediffusionmod

elon

book

sales(n

=4)

Beck

(2007)

offersan

exem

plaryfit

ofan

elaboratediffusionmod

elon

book

sales(n

=4).

Deschâtres/Sornette

(2005)

analyzebo

oks‘salespatterns

onAmazon

.com

(n=138).

Both

stud

iesfin

dtw

omajor

patterns

ofdiffusion:

externaldiffusion(successfullstart,strong

decaytren

d)

internaldiffusion(bellshape

dcurve,moresustainablegrow

thinpo

pularity)

Both

stud

iesofferno

explan

ationof

diffusionalheterogen

eity.

Thispresen

tatio

nlinks

varyingpatterns

toreaders‘know

ledgeon

writers

#4

MarcKeuschnigg

Thispresen

tatio

nlinks

varyingpatterns

toreadersknow

ledgeon

writers.

30.11.2009

BasicMod

elsof

Diffusion

EIM

BasicMod

elsof

Diffusion:

EIM

ExternalInflu

ence

Mod

el

,with

a>0andN*=

=1.

))(

1()(

tF

at

ft

tf)(

.1on

a=01

.04rate of diffusio

a=0.1

a=0.04

0

020

4060

8010

0t

a=

01

a=

004

a=Parameter

ofInno

vatio

n,ExternalInflu

ence

a=

0,1

a=

0,04

#5

MarcKeuschnigg

Mostly

relevant

forb

ooks

byestablishedwriters?

30.11.2009

BasicMod

elsof

Diffusion

EIM

BasicMod

elsof

Diffusion:

EIM

Exam

pleforExternalDiffusion

pH.M

ankell,DieBrandm

auer

associated

star

power

(existingknow

ledgeon

writer,high

med

iacoverage)

11 10 20 30sales rank

40 50

020

4060

80ru

n tim

e in

Top

50

#6

MarcKeuschnigg

30.11.2009

BasicMod

elsof

Diffusion

IIMBa

sicMod

elsof

Diffusion:

IIM

InternalInflu

ence

Mod

el ,with

and

.))(

1()(

)(

tF

tbF

tf

0)0

(tF

0b

b03

.06on

b=0.3

b=0.15

F(t=

0)=0,01

.03rate of diffusio

()

0

020

4060

8010

0t

b=

03

b=

015

b=Parameter

ofIm

itatio

n,Internal/SocialInfluen

ce

b=

0,3

b=

0,15

#7

MarcKeuschnigg

Mostly

relevant

forn

ewcomer

books?

30.11.2009

BasicMod

elsof

Diffusion

IIMBa

sicMod

elsof

Diffusion:

IIM

Exam

pleforInternalDiffusion

pL.Sw

ann,Glenn

kill

noassociated

star

power

1 10 20 30sales rank

40 50

020

4060

run

time

in T

op 5

0

#8

MarcKeuschnigg

30.11.2009

Integrated

Mod

elof

Diffusion

MIM

Integrated

Mod

elof

Diffusion:

MIM

Mixed

Influ

ence

Mod

elEstim

ationof

both,EIand

II,ispo

ssible!

f,

,p

))(

1())(

()(

tF

tbF

at

f Exam

ples

forMIM

’sfle

xibility:

BlockbusterDiffusion

a=0.04

,b=0.01

New

comer

Diffusion

a=0.001,

b=0.1

Blo

ckbu

ster

Diff

usio

n

.04on

New

com

er D

iffus

ion

.02rate of diffusi

0

020

4060

8010

0t

a =

0,04

;b =

0,0

1a

= 0,

001;

b =

0,1

#9

MarcKeuschnigg

30.11.2009

a0,

0;b

0,0

a0,

00;b

0,

Integrated

Mod

elof

Diffusion

MIM

Integrated

Mod

elof

Diffusion:

MIM

Mixed

Influ

ence

Mod

elEstim

ationof

both,EIand

II,ispo

ssible!

f,

,p

))(

1())(

()(

tF

tbF

at

f Exam

ples

forMIM

’sfle

xibility:

BlockbusterDiffusion

a=0.04

,b=0.01

New

comer

Diffusion

a=0.001,

b=0.1

Hypothe

ses:

Hypothe

ses: H1

aEstablished

>a

New

comer

H2

bEstablished

<b

New

comer

#10

MarcKeuschnigg

30.11.2009

Estim

ationof

aandb

Data:

Novelsranked

Top50

inGermany(2001–2006,n

=798).

Olb

ki

ld

dhi

hkdT

50f

di

f10

k354

Estim

ationof

aandb

Onlybo

oksinclud

ed,w

hich

ranked

Top50

foradu

ratio

nof

10weeks,n

=354.

Thus,354

diffusions

areexam

ined

.

Dep

.variable:

f(t)=y t,invertedsalesrank

int(range

1–50).

Regressors:

F(t)=x t,cum

ulated

priorinverted

salesranksinclud

ingt–1.

Non

linearleastsquares(NLLS)

offersacontinou

sestim

ationof

MIM

andthus

book

specifica,b

(e.g.Srinivasan/Mason

1989):

tt

tt

ux

bxa

y)

1()(

aandbareestim

ated

for3

54diffusions

each,using

354NLLSregression

s

tt

tty

)()

(

#11

MarcKeuschnigg

30.11.2009

Explanationof

aandb

OLS

Regression

,rob

uststand

arderrors.N

LLSestim

ates

used

asde

p.variables(lo

ga,logb).

Explanationof

aandb

Regressors:

establishe

dwriter

(dum

my,1ifprevious

Top50

titlesexist)

publishe

r’smarketin

gpo

wer

(#of

publishe

dTo

p50

titlesin2001

06)

book’squ

ality

(#of

Amazon

stars)

logruntim

e(lo

g#weeks

ranked

inTop50)

logruntim

e(lo

g#weeks

ranked

inTo

p50)

externalinflu

ence

(loga)

12

3establishe

dwriter

0.165*

0.133†

0.082

(0.070

)(0.056

)(0.035

)marketin

g0.006*

0.007*

(0.066

)(0.079

)qu

ality

0.153*

*

(0.090

)logruntim

e1.690*

**1.697*

**1.691*

**

(0.81

8)(0.82

2)(0.81

9)(

)(

)(

)genre

controlled

constant

1.686*

**1.592*

**0.927*

*

n354

354

354

R2ad

j0665

0669

0674

#12

MarcKeuschnigg

30.11.2009

Unstand

.coe

fficents,standardized

coefficientsinparenthe

ses,

†p<0.1,*p<0.05,**p<0.01,***

p<0.001.

R2ad

j.0.665

0.669

0.674

Explanationof

aandb

OLS

Regression

,rob

uststand

arderrors.N

LLSestim

ates

used

asde

p.variables(lo

ga,logb).

Explanationof

aandb

Regressors:

establishe

dwriter

(dum

my,1ifprevious

Top50

titlesexist)

publishe

r’smarketin

gpo

wer

(#of

publishe

dTo

p50

titlesin2001

06)

book’squ

ality

(#of

Amazon

stars)

logruntim

e(lo

g#weeks

ranked

inTop50)

logruntim

e(lo

g#weeks

ranked

inTo

p50)

externalinflu

ence

(loga)

12

3internalinflu

ence

(logb)

12

3establishe

dwriter

0.165*

0.133†

0.082

(0.070

)(0.056

)(0.035

)marketin

g0.006*

0.007*

(0.066

)(0.079

)

0.212*

0.224*

0.211*

(0.08

0)(0.08

4)(0.07

9)0.002

0.002

(0.023

)(0.021

)qu

ality

0.153*

*

(0.090

)logruntim

e1.690*

**1.697*

**1.691*

**

(0.81

8)(0.82

2)(0.81

9)

0.139*

(0.073

)1.843*

**1.846*

**1.840*

**

(0.78

6)(0.78

7)(0.78

5)(

)(

)(

)genre

controlled

constant

1.686*

**1.592*

**0.927*

*

n354

354

354

R2ad

j0665

0669

0674

()

()

()

controlled

3.066*

**3.029*

**2.523*

**

354

354

354

0631

0631

0639

#13

MarcKeuschnigg

30.11.2009

Unstand

.coe

fficents,standardized

coefficientsinparenthe

ses,

†p<0.1,*p<0.05,**p<0.01,***

p<0.001.

R2ad

j.0.665

0.669

0.674

0.631

0.631

0.639

TestforRe

liabilityMultiLevelA

nalysis

TestforRe

liability:MultiLevelA

nalysis

TwoLevelA

nalysis

Efficient,integratedestim

ationof

book

characteristics‘effectson

diffusioncurves

(see

Rossman

etal.2008on

payolainpo

pmusicradio).

Dep

.variable:

y it,boo

ki‘s

inverted

salesrank

int

Regressors

Level1:x it,xit2 ,cumulated

inverted

ranks(Bass’linearizatio

n);w

ithinbo

okvaria

tion

Level2:

book

characteristicsas

interactions

ofx ix i2 ;betw

eenbo

oksvaria

tion

Level2:

book

characteristicsas

interactions

ofx it,xit;betweenbo

oksvaria

tion

writer’sstar

power

publishe

r’smarketin

gpo

wer

quality

logruntim

e

#14

MarcKeuschnigg

30.11.2009

TestforRe

liabilityMultiLevelA

nalysis

Effectsof

book

characteristicson

externalandinternalinflu

ence.

TestforRe

liability:MultiLevelA

nalysis

Rand

omEffectsMod

el.

Estim

ationby

Restricted

Maxim

umLikelihoo

d(REM

L),e.g.Snijders/Bo

sker

(1999).

R2with

in:0.55,R

2betw

een:

0.87.Resultsextracted.

externalinflu

ence

internalinflu

ence

(a)

%change

(b)

%change

establishe

dwriter

+0.008***

+17.4

–0.023***

–30.7

(0.001)

(0.005)

marketin

g0.000

0–0.000*

0(0.000)

(0.000)

Unstand

.coe

fficents,stand

arderrorsinparenthe

ses,*p<0.05,**p<0.01,***

p<0.001.

quality

–0.002

–4.3

+0.012**

+16.0

(0.001)

(0.004)

#15

MarcKeuschnigg

30.11.2009

TestforRe

liabilityMultiLevelA

nalysis

Effectsof

book

characteristicson

externalandinternalinflu

ence.

TestforRe

liability:MultiLevelA

nalysis

Rand

omEffectsMod

el.

Estim

ationby

Restricted

Maxim

umLikelihoo

d(REM

L),e.g.Snijders/Bo

sker

(1999).

R2with

in:0.55,R

2betw

een:

0.87.Resultsextracted.

externalinflu

ence

internalinflu

ence

(a)

%change

(b)

%change

establishe

dwriter

+0.008***

+17.4

–0.023***

–30.7

(0.001)

(0.005)

marketin

g0.000

0–0.000*

0(0.000)

(0.000)

Unstand

.coe

fficents,stand

arderrorsinparenthe

ses,*p<0.05,**p<0.01,***

p<0.001.

quality

–0.002

–4.3

+0.012**

+16.0

(0.001)

(0.004)

Results

from

twostep

approach:

+17

/8%

–21

%

#16

MarcKeuschnigg

30.11.2009

TestforVa

lidity

Lookingat

Readers

Which

diffusionchanne

lisbe

ingused

tostim

ulateindividu

aladop

tion?

TestforVa

lidity

:Loo

king

atRe

aders

Which

diffusionchanne

lisbe

ingused

tostim

ulateindividu

aladop

tion?

Basichypo

theses:

ypBo

oksby

establishe

dwritersareadop

tedthru

externalstim

ulation.

Booksby

newcomersareadop

tedthru

internal,socialstim

ulation.

Link

tosocialne

tworkanalysis:

Sociallywellembe

dded

readers(e.g.city

size)ado

ptthru

internalstim

ulation.

y(

gy

)p

#17

MarcKeuschnigg

30.11.2009

Micro

LevelA

nalysis

Data

GfK

Consum

erPane

l200304;20,000individu

alparticipants(Germanson

ly).

Micro

LevelA

nalysis

Sample

Theanalysisisconfined

tohardcoverbo

oks,which

wereranked

Top50.

Togetreasonablegrou

psizes,on

lybo

okswith

atotalnum

berof

30ob

served

readersareinclud

ed.

Thisleadsto

1,18

1ob

served

purchasesiof2

4bo

oksj.

#18

MarcKeuschnigg

30.11.2009

Micro

LevelA

nalysis

Data

GfK

Consum

erPane

l200304;20,000individu

alparticipants(Germanson

ly).

Micro

LevelA

nalysis

Sample

Theanalysisisconfined

tohardcoverbo

oks,which

wereranked

Top50.

Togetreasonablegrou

psizes,on

lybo

okswith

atotalnum

berof

30ob

served

readersareinclud

ed.

Thisleadsto

1,18

1ob

served

purchasesiof2

4bo

oksj.

Dep

var

How

didyoulearnabou

tthe

book

youbo

ught?“

Dep

.var.„H

owdidyoulearnabou

tthe

book

youbo

ught?

Stim

ulus

freq

.%

freq

.%

1med

ia147

12,5

2advertisem

ent

9278

2advertisem

ent

927,8

3catalogue

391

33,1

ExternalInflu

ence

(y=0)

956

814

shop

decor

296

25,1

5bo

okseller’stip

302,5

6wordof

mou

th129

10,9

InternalInflu

ence

(y=1)

225

197

bestsellerlist

968,1

npu

rchases

1181

1181

#19

MarcKeuschnigg

30.11.2009

npu

rchases

1.181

1.181

mbo

oks

2424

Micro

LevelA

nalysis

Hierarchicallogistic

regression

with

rand

omintercep

ts

Micro

LevelA

nalysis

Dicho

tomou

sde

p.var.:

y ij=1,individu

aladop

tionthru

internalstim

ulation

y ij=0,individu

aladop

tionthru

externalstim

ulation

Regressors

Level1:

buyercharacteristics;

with

inbo

okvaria

tion

embe

dded

ness/socialcapita

lcity

size

(5categories,quasimetric)

education

(dum

my,1if

Fachho

chschu

lreife)

high

income

(dum

my,1if

3,000EU

R)

sex

(dum

my,1ifbu

yerisfemale)

weekof

purchase

(#weeks

sincerelease)

Level2:

book

characteristics;

betw

eenbo

oksvaria

tion

establishe

dwriter

(dum

my,1ifprevious

Top50

titlesexist)

establishe

dwriter

(dum

my,1ifprevious

Top50

titlesexist)

publ’smarketin

gpo

wer

(dum

my,1ifbe

longingto

conglomerate)

logruntim

e(lo

g#weeks

ranked

inTo

p50)

#20

MarcKeuschnigg

30.11.2009

Micro

LevelA

nalysis

Odd

sforsocialcontagion.

hf

bk

Micro

LevelA

nalysis

1,181pu

rchasesof

24bo

oks.

Dicho

tomou

sde

p.variable:1ifindividu

aladop

tionby

internalstim

ulus.

Odd

sRatio

s%change

establishe

dwriter

0.550*

*–45.0

marketin

g0.668*

–33.2

logruntim

e1.538*

**+53.2

logruntim

e1.538

+53.2

citysize

1.164*

+16.4

high

education

1.591*

*+59.1

high

income

1.523*

*+52.3

female

1.745*

*+74.5

weekof

purchase

1008

+08

Odd

sratio

s(e),

%change

([e

–1]

100),

†p<0.1,*p<0.05,**p<0.01,***

p<0.001.

weekof

purchase

1.008

+0.8

mpu

rchases

1,181

nbo

oks

24Nag

elkerkes

R20.079

#21

MarcKeuschnigg

30.11.2009

Summary

Summary

Diffusionof

booksdiffersby

writers‘starpo

wer,i.e.reade

rs‘kno

wledgeon

writers.

Book

levelanalysis

Diffusionforestablishe

dwritersfollowsablockb

ustershap

edcurve(hintsexternaldiffusion).

Diffusionforne

wcomersfollowsahu

mpshap

edcurve(hintsinternaldiffusion).

Reader

levelanalysis

Inde

ed,estab

lishe

dbo

oksgeta

dopted

prim

arily

byexternalstim

ulus.

Inde

ed,new

comer

booksgeta

dopted

prim

arily

bysocialstim

ulus.

Also:

Type

ofindividu

aladop

tionde

pend

son

Also:

Type

ofindividu

aladop

tionde

pend

son

reader‘sne

tworkem

bedd

edne

ss:

wellcon

nected

agentsmakegreateruseof

sociallearning.

reader‘ssex:

femalereadersmakegreateruseof

sociallearning.

#22

MarcKeuschnigg

30.11.2009

Thankyouallfor

your

attention!

References

BassF1969:A

New

Prod

uctG

rowth

Mod

elforCo

nsum

erDurables.Managem

entS

cien

ce15

:215

227.

gBe

ckJ2

007:

TheSalesEffectof

Wordof

Mou

th:A

Mod

elforCreativeGoo

dsandEstim

ates

forNovels.JournalofC

ulturalEcono

mics31:5

23.

Clem

entM

,eta

l.2006:D

iffusionof

Hed

onicGoo

ds:A

Literature

Review

.Internatio

nalJou

rnalon

Med

iaManagem

ent8

:155

163.

DeschâtresF,Sornette

D2005:The

Dynam

icsof

Book

Sales:Endo

geno

usversus

Exogen

ousShocks

inCo

mplex

Networks.PhysicalReviewE72.

Mahajan

V,Peterson

R1985:M

odelsforInno

vatio

nDiffusion.Be

verlyHills:Sage

Publications

.Ro

ssman

G,et

al.20

08:Mod

ellingDiffusionof

Multip

leInno

vatio

nsviaMultilevel

DiffusionCu

rves:Payola

inPo

pMusicRa

dio.

Sociological

Metho

dology

38:2

0123

0.SnijdersT,Bo

sker

R1999:M

ultilevelAnalysis.AnIntrod

uctio

nto

BasicandAdvancedMultilevelMod

eling.Thou

sand

Oaks:Sage

Publications.

Srinivasan

V,Mason

C1986:N

onLine

arLeastS

quares

Estim

ationof

New

Prod

uctD

iffusionMod

els.Marketin

gScience5:16917

8.V

dB

ltCJ

hiY2005

NP

dtD

iffi

ithIfl

til

dI

itt

Wki

PU

iit

fPl

i

#23

MarcKeuschnigg

30.11.2009

Vande

nBu

lteC,JoshiY

2005:N

ewProd

uctD

iffusionwith

Influ

entia

lsandIm

itators.W

orking

Pape

r,University

ofPenn

sylvania.

App

endix

#24

MarcKeuschnigg

30.11.2009