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1 Is Pirates’ Loss Consumers’ Gain? Software Piracy and Bundling Strategy Xiong Zhang School of Economics and Management, Beijing Jiao Tong University, Beijing, China [email protected] Wei T. Yue Department of Information Systems, City University of Hong Kong, Hong Kong [email protected] Wendy Hui Faculty of Business, Lingnan University, Hong Kong [email protected] Abstract Unlike traditional software products which rely on product keys to manage software piracy, Internet-enabled software services utilize the Internet infrastructure to continuously manage and deter the problem. The emergence of Internet-enabled software services have led to a different approach to piracy management. In this note, we consider a firm’s bundling decision intertwining with its piracy deterrence strategy. Similar to findings in the extant product bundling literature, we find that mixed bundling is the optimal strategy when software piracy is not considered. This result can be extended to the case where there is piracy but no piracy deterrence. Although pure bundling is not an optimal strategy, it exhibits greater resiliency against the threat of piracy. The presence of software piracy also leads to greater surplus for the legitimate users. When piracy deterrence measures are used, pure bundling may be the optimal strategy due to a combination of competition and cannibalization effects existing in mixed bundling. At the same time, consumers may also enjoy greater surplus in pure bundling than in mixed bundling, making pure bundling the preferred strategy for both the firm and the consumers. The use of piracy deterring measures generally allows the firm to extract surplus from consumers more effectively, giving rise to a “pirates’ loss is consumers’ loss” outcome. Our results provide insights into the emerging Internet-enabled software service phenomenon; and contribute to the long established literature on piracy and bundling. Keywords: Software Product, Internet-Enabled Software Service, Bundling Strategy, Software Piracy, Digital Rights Management

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Page 1: Is Pirates’ Loss Consumers’ Gain? Software Piracy and ... › conference › csim2018 › assets › ... · piracy, some studies have considered the use of pricing schedules (Sundararajan,

1

Is Pirates’ Loss Consumers’ Gain? Software Piracy and Bundling Strategy

Xiong Zhang

School of Economics and Management, Beijing Jiao Tong University, Beijing, China

[email protected]

Wei T. Yue

Department of Information Systems, City University of Hong Kong, Hong Kong

[email protected]

Wendy Hui

Faculty of Business, Lingnan University, Hong Kong

[email protected]

Abstract

Unlike traditional software products which rely on product keys to manage software

piracy, Internet-enabled software services utilize the Internet infrastructure to

continuously manage and deter the problem. The emergence of Internet-enabled software

services have led to a different approach to piracy management. In this note, we consider

a firm’s bundling decision intertwining with its piracy deterrence strategy. Similar to

findings in the extant product bundling literature, we find that mixed bundling is the

optimal strategy when software piracy is not considered. This result can be extended to

the case where there is piracy but no piracy deterrence. Although pure bundling is not an

optimal strategy, it exhibits greater resiliency against the threat of piracy. The presence

of software piracy also leads to greater surplus for the legitimate users. When piracy

deterrence measures are used, pure bundling may be the optimal strategy due to a

combination of competition and cannibalization effects existing in mixed bundling. At

the same time, consumers may also enjoy greater surplus in pure bundling than in mixed

bundling, making pure bundling the preferred strategy for both the firm and the

consumers. The use of piracy deterring measures generally allows the firm to extract

surplus from consumers more effectively, giving rise to a “pirates’ loss is consumers’

loss” outcome. Our results provide insights into the emerging Internet-enabled software

service phenomenon; and contribute to the long established literature on piracy and

bundling.

Keywords: Software Product, Internet-Enabled Software Service, Bundling Strategy,

Software Piracy, Digital Rights Management

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2

Is Pirates’ Loss Consumers’ Gain? Software Piracy and Bundling Strategy

1. Introduction

Bundling and piracy are two pervasive phenomena in the software industry. However, few studies have

tied these two phenomena together. Software bundling has been studied under the realm of information

goods (Bakos & Brynjolfsson, 1999; Geng, Stinchcombe, & Whinston, 2005) which exhibit negligible

marginal costs and can be bundled rather easily without much overhead. Indeed, several studies have

noted that bundling information goods can be an optimal strategy for firms if the consumer valuation of

subsequent goods in the bundle does not decrease quickly (Geng et al., 2005). However, information

goods are known to be susceptible to piracy due to the ease of duplication. To mitigate the threat of

piracy, some studies have considered the use of pricing schedules (Sundararajan, 2004), digital rights

management (DRM) (Chen & Png, 2003; Sundararajan, 2004), versioning (Lahiri & Dey, 2013) and

sampling through piracy (Chellappa & Shivendu, 2005).

Following the emergence of the ubiquitous Internet-enabled technology, many firms have begun

to include Internet-enabled auxiliary components in their traditional software products. For example,

Microsoft offers standalone “on-premises” Microsoft Office as well as Office 365, which comprises

additional auxiliary software services. While software firms have long used bundling as a selling

strategy, such Internet-based components introduce new sets of measures for mitigating piracy. This is

because firms typically apply encryption as DRM to protect software distributed through DVD,

regardless of whether the content is a single software product or a software bundle. When software is

distributed through the Internet as a service, the firm can engage in authentication and continuous

monitoring of their software services. The linkage between the on-premises software and the Internet-

enabled components also means that the firm can extend the online DRM to the on-premises software.

For example, Microsoft had previously relied on Volume Licensing Keys (VLKs) to check for on-

premises software licensing. This scheme is being replaced increasingly by Multiple Activation Keys

(MAK) and Key Management Server (KMS) keys—a form of online DRM that facilitates periodic

licensing check1. The new development presents a novel intertwining effect on software bundling and

software piracy, thus underscoring the relevancy of this topic.

Gopal and Gupta (2010) were the first to study the interaction between bundling and piracy. They

put forward the idea that applying pure bundling can potentially mitigate piracy while increasing profit

at the same time. The intuition is that, when products are bundled collectively, it makes it easier for law

enforcement agencies to detect a pirated product, thus generating a greater deterrence effect. Therefore,

all things being equal, deterrence controls will be more effective. Integrating with demand pooling for

software products of different consumer valuations, bundling may allow the firm to earn higher profits

while decreasing the piracy level for all the products in the bundle. More interestingly, higher profits can

result when the piracy level for one of the products in the bundle is higher. These results provide an

important insight into the underlying mechanism that makes bundling a potential piracy deterrence

instrument. However, the study mainly considers consumers buying the products either individually

(pure components) or as a bundle, and does not analyze mixed bundling, i.e., providing consumers with

the option of buying products individually or as a bundle. In the literature, mixed bundling has often

been found to represent a supreme strategy in view of its ability in performing price discrimination (e.g.,

Adams & Yellen, 1976) and improving product cost sharing (Guiltinan, 1987). Thus, our aim here is to

examine which form of bundling (pure or mixed) is more desirable when piracy is present.

1 For more details, see https://technet.microsoft.com/en-us/library/ff793434.aspx; https://www.microsoft.com/en-

us/licensing/existing-customer/product-activation.aspx

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We follow the common approach taken in the bundling literature—a monopolist firm making the

choice of selling the software product and associated services using one of the following strategies: pure

components (the software product only), pure bundling (the bundle consisting of the software product

and the auxiliary Internet-enabled component only) and mixed bundling (both the software product and

the bundle). Specifically, we are interested in the following questions: 1. What are the effects of piracy

on the individual selling strategies? 2. How does piracy change the firm’s optimal bundling choice? 3.

What will be the resulting consumer welfare? Essentially, the different selling strategies involve different

combinations of the product and the bundle. The piracy levels are different depending on whether the

choice involves the product and/or the bundle. Our stylized models analytically compare the bundling

strategies under three scenarios: no piracy, piracy is present, and piracy is present while the firm applies

DRM.

Although this work draws much of its inspiration from Gopal and Gupta (2010), our objectives

and analysis approach are very different. First, rather than just illustrating the use of bundling as a piracy

deterrence strategy, we focus on examining whether the existent insights from the bundling literature

would change when piracy is introduced into the problem. Second, our work focuses on the emerging

Internet-enabled service phenomenon, so our problem scope is much more relevant under the new

Internet-enabled cloud-based context. Finally, we do not model the problem using the private goods club

approach, where piracy demand depends on the number of individuals sharing the individual product.

Instead, we follow the model setting of the traditional bundling literature, by presenting the pirated

product as simply another option under the consumer’s choice set, along with the legitimate product.

This approach makes our work more comparable to the extant bundling literature. As bundling models

are known to be notoriously difficult to solve mathematically, our approach also allows us to preserve

the mathematical tractability and thus arrive at more conclusive results.

Indeed, when one does not consider piracy, mixed bundling is generally found to be the superior

strategy. Pure bundling offers only one bundle to the market. The firm needs to set a price to extract as

much surplus from the consumers as possible, while making sure that the demand for the bundle is as

large as possible. The two objectives are in conflict with each other. The optimal bundle price is where

both surplus extraction and the quantity demanded are optimally balanced. With mixed bundling, the

firm can increase the bundle price to extract more surplus from the high type (bundle) consumers, while

at the same time set the product price at a reasonable level to keep the low type (product) consumers.

Hence, the price discrimination allows the firm to address the conflicting objectives more effectively.

When piracy is considered and the firm does not apply DRM, the firm earns lower profits under

all strategies. Although mixed bundling is still the optimal strategy, pure bundling is more resilient to

the threat of piracy, i.e., the decline in profits is less significant. The presence of pirated product in the

market, in essence, creates a “competition” effect to the legitimate product and bundle, thus lowering

the firm’s profits. The effect on profitability is more prominent under mixed bundling because both

segments (the product and the bundle) are affected by piracy, whereas only the bundle segment is

affected under pure bundling. We find that piracy generally increases consumer surplus while bundling

results in a “pirates’ gain is consumers’ gain” outcome at the expense of the firm. Note that this result

holds even if we do not consider the surplus gained by pirates from consuming the pirated product.

Incidentally, Vernik, Purohit and Desai (2011) find the presence of piracy may also lead to higher

consumer surplus due to increased competition (hence lower prices) between different sellers. In our

context, piracy creates a direct competition effect between the authentic and the pirated products.

When DRM is considered, the firm earns higher profits under both pure and mixed bundling.

Compared to the case with no piracy deterrence, DRM increases the piracy cost and allows the firm to

“re-extract” consumer surplus by raising prices under both bundling strategies; it also increases the

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bundle demand for pure bundling. Thus, the introduction of DRM leads to a “pirates’ loss is consumers’

loss” outcome. Contrary to conventional wisdom, pure bundling can turn out to be the optimal strategy.

The intuition is that pirated software can be a close substitute to the product in mixed bundling. The

competition effect forces the firm to set a lower product price. However, a lower product price can

cannibalize the demand of the bundle. If the competition and the cannibalization effects are large and

the online DRM is effective, pure bundling can be more profitable. This result is in contrast to previous

findings, albeit under different modeling settings2, that not applying DRM could lead to higher profits

for the firm due to competition induced price increases (Jain, 2008; Vernik et al., 2011). In our work,

pure bundling does not eliminate piracy completely and can result in a higher consumer surplus than

mixed bundling. Interestingly, this situation can co-exist with pure bundling being the optimal strategy,

due to the competition and cannibalization effects in mixed bundling.

2. Literature Review

Tracing back to the 1960s, one finds an extensive line of studies examining product bundling. The

optimal bundling strategy has been at the center of discussions. The following are some major findings:

mixed bundling has been found to be an optimal strategy under general settings (Adams & Yellen, 1976;

McAfee, McMillan, & Whinston, 1989; Schmalensee, 1984; Stremersch & Tellis, 2002); pure bundling

is the optimal strategy when product values are negatively correlated (Adams & Yellen, 1976; Salinger,

1995); the pure components strategy is the least favorable when the marginal cost is low and the mean

valuation of the product is high (Schmalensee, 1984). When pure bundling and mixed bundling are

compared, mixed bundling is more profitable if the consumers have substantial differences

(heterogeneity) in the valuation of the second product (Pierce & Winter, 1996). Recently, some studies

have extended the bundling studies by incorporating other elements, such as network externalities effect

(Pang & Etzion, 2012; Prasad, Venkatesh, & Mahajan, 2010) and capacity limit (Cao, Stecke, & Zhang,

2015). In this note, we extend the bundling literature by considering piracy, which is especially relevant

to information goods.

Our work is also relevant to the stream of studies that examines the economic impact on the use

of piracy mitigation measures on information goods. Gopal and Sanders (1997) investigate the use of

preventive or deterrent controls to fight against piracy and find that the latter approach can lead to higher

profits for the firm. Sundararajan (2004) finds that the ability of the firm to conduct price discrimination

will reduce the protection level of DRM. Chen and Png (2003) find that a tax on copying will induce the

firm to increase price and reduce DRM enforcement, which in equilibrium, will propel the firm to rely

more on lower price rather than DRM to mitigate piracy. Lahiri and Dey (2013) find that the presence

of piracy may increase the incentive for the firm to invest in product quality to differentiate from the

pirated product. Some other studies have found that the presence of piracy can lead to a higher profit for

the firm. For instance, allowing sampling of information goods through piracy can be the optimal

strategy for the firm (Chellappa & Shivendu, 2005). Others have found that the externality effect

generated through piracy makes piracy “beneficial” to the firm (e.g., Conner & Rumelt, 1991). In the

digital entertainment context, Vernik, Purohit and Desai (2011) find the elimination of DRM may reduce

piracy because of competition-induced price declines. However, this reduction in piracy does not

guarantee higher profits for the firm. Our work is related to the studies mentioned above by specifically

considering how piracy affects sales and how the firm uses DRM to tackle piracy by reducing the utility

of the pirated product.

2 Under a duopoly setting, Jain (2008) finds that the two firms choose to remove DRM, which leads to the outcome of less

competition and higher price. Purohit and Desai (2011) consider the sale of information goods (music) throgh either the retail

channel or online channel. The online channel is in direct competition with the priated product. Moeoever, DRM can only be

applied to the online channel. Removing DRM on donwloads (online channel) may lead to price increase and hihger profits.

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3. Model Setting

In this section, we present the general setting of our models. We assume that an individual’s reservation

value for the software product (Product) is homogeneous and is denoted by 𝑟, which is a constant. The

individual’s reservation for the software bundle (Bundle) is given by 𝑟 + 𝜃𝑏, where 𝜃𝑏 is simply the net

additive value of the Bundle compared to that of the Product. It is a random variable 𝜃𝑏 ∈ [0, �̅�𝑏] with

density 𝑓(𝜃𝑏).

The goods of interest include (1) the “on-premises” software product and (2) an associated

auxiliary cloud component, which cannot be sold as a standalone good3. We assume the marginal cost

for the Product is zero and the marginal cost for the Bundle is a small but non-negligible constant. At

the consumer end, piracy does not lead to any product quality degradation4. If the firm does not use

DRM, the piracy cost is negligible. If DRM is used, the piracy cost is increased but the effectiveness of

the on-premises DRM and the online DRM can be different. Each consumer will only buy either the

Product or the Bundle. On the other hand, the firm will offer consumers one of the following options:

Product only (pure components), Bundle only (pure bundling) or both the Product and the Bundle (mixed

bundling). We denote these options as PC, PB and MB, respectively. We present these models in the

next three subsections. We first present the base model (Model 1), where both piracy and DRM are not

modeled. In Model 2, we assume that there is a pirated version of the product. In Model 3, the firm can

implement DRM.

3.1 Model 1: No Piracy, No DRM

In Pure Component strategy, the firm would set its price 𝑝𝑝∗ = 𝑟. All consumers will buy the Product.

With a normalized population of one, the firm’s profit is 𝑟, assuming zero marginal cost of production

for software (Bakos & Brynjolfsson, 1999). The total consumer surplus is 𝐶𝑆∗ = 𝑟 − 𝑟 = 0. Thus, an

increase in 𝑟 increases the Product price and the firm’s profit, but has no effect in the total consumer

surplus.

In Pure Bundling strategy, the firm offers only the Bundle at the price as 𝑝𝑏. An individual buying

the Bundle must satisfy 𝑏 > 𝑝𝑏 − 𝑟. The firm’s profit per Bundle sale is 𝑝𝑏 − 𝑐, where 𝑐 is the cost of

providing a Bundle. The firm’s total profit is 𝜋 = (𝑝𝑏 − 𝑐)[1 − 𝐹(𝑝𝑏 − 𝑟)]. The first order condition is 𝑑𝜋

𝑑𝑝𝑏= 1 − 𝐹(𝑝𝑏 − 𝑟) − (𝑝𝑏 − 𝑐)𝑓(𝑝𝑏 − 𝑟) = 0, or

𝑓(𝑝𝑏−𝑟)

1−𝐹(𝑝𝑏−𝑟)=

1

𝑝𝑏−𝑐. (1)

PB is more profitable than PC if and only if 𝑟 < (𝑝𝑏∗ − 𝑐)[1 − 𝐹(𝑝𝑏

∗ − 𝑟)]. We assume the above

condition, 𝑟 < (𝑝𝑏∗ − 𝑐)[1 − 𝐹(𝑝𝑏

∗ − 𝑟)], to be true. In other words, 𝑐 is small and the proportion of

people valuing the additional cloud service in Bundle reasonably highly is sufficiently large.

T

h

e

l

e

f

t

h

a

n

d

s

3 This type of mixed bundling strategy is referred as MB-1 strategy where only {product 1} and {product 1, product 2} are

offered (Prasad et al., 2010). 4 Literature has assumed the application of DRM affects product quality. For example, Sundararajan (2004) assumes the

application of DRM will reduce the quality of the pirated product. Vernik, Purohit and Desai (2011) find that DRM reduces

the utility to legal users consuming digital content.

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6

𝑓(𝑥)

1−𝐹(𝑥)=

1

𝑥+𝑟−𝑐, (2)

w

h

e

r

e

≡𝑝𝑏−𝑟. Let the solution to Equation 𝑓𝑥1−𝐹𝑥=1𝑥+𝑟−𝑐, (2) be

𝑥∗. An increase in 𝑟 tends to shift the right hand side towards the left, and thus decrease 𝑥∗. If 𝑥∗ is

decreased, 𝐹(𝑥∗) is also decreased and, since 1 − 𝐹(𝑥∗) , which is exactly the Bundle demand, is

increased. Since both the price and demand increases with 𝑟, the firm also earns higher profits with a

higher 𝑟.

Lemma 1a (No piracy, No DRM; Pure Bundling): An increase in 𝑟 increases 𝑝𝑏∗5, the equilibrium demand

1 − 𝐹(𝑝𝑏∗ − 𝑟) and the equilibrium profit (𝑝𝑏

∗ − 𝑐)[1 − 𝐹(𝑝𝑏∗ − 𝑟)].

We now consider the total consumer surplus: 𝐶𝑆∗ = ∫ (𝑟 + 𝜃𝑏 − 𝑝𝑏∗ )𝑓(𝜃𝑏)

�̅�𝑏

𝑝𝑏∗ −𝑟

𝑑𝜃𝑏. The lower

limit 𝑝𝑏∗ − 𝑟, which is 𝑥∗, decreases with r, while the integral (𝑟 + 𝜃𝑏 − 𝑝𝑏

∗ )𝑓(𝜃𝑏) increases with r. This

implies that the consumer surplus grows with 𝑟.

Lemma 1b (No piracy, No DRM; Pure Bundling): The equilibrium total consumer surplus increases with 𝑟.

Lemma 1a suggests that an increase in the valuation of the software product, 𝑟, leads to an

increase in the Bundle price, which increases the monopolistic firm’s profit. However, according to

Lemma 1b, the increase in valuation is not completely transferred to the firm; the consumers also share

part of the value increase.

In Mixed Bundling strategy, an individual has the choice to buy the Product or the Bundle. An

individual buying the Product must satisfy 𝑟 > 𝑝𝑝 and 𝑏 < 𝑝𝑏 − 𝑝𝑝. We assume the first condition to

be true. An individual buying the Bundle must satisfy 𝑏 > 𝑝𝑏 − 𝑟 and 𝑏 > 𝑝𝑏 − 𝑝𝑝.

We assume that the Bundle can be more profitable than the Product, i.e., �̅�𝑏 − 𝑐 > 0, the value-

added by the cloud service is larger than the cost of offering the cloud service for at least some

consumers. The firm’s total profit is 𝜋 = 𝑝𝑝𝐹(𝑝𝑏 − 𝑝𝑝) + (𝑝𝑏 − 𝑐)[1 − 𝐹(𝑝𝑏 − 𝑝𝑝)]. Differentiating

the above equation with respect to 𝑝𝑝 and 𝑝𝑏, we arrive at the following first order conditions:

𝑑𝜋

𝑑𝑝𝑝= 𝐹(𝑝𝑏 − 𝑝𝑝) + (𝑝𝑏 − 𝑐 − 𝑝𝑝)𝑓(𝑝𝑏 − 𝑝𝑝) = 0

𝑑𝜋

𝑑𝑝𝑏= [1 − 𝐹(𝑝𝑏 − 𝑝𝑝)] − (𝑝𝑏 − 𝑐 − 𝑝𝑝)𝑓(𝑝𝑏 − 𝑝𝑝) = 0

If all individuals are willing to buy the Product in the first place, the firm would not offer Bundle unless

it is more profitable than Product, i.e., 𝑝𝑏 − 𝑐 − 𝑝𝑝 > 0. However, if Bundle is more profitable than

Product, we have 𝑑𝜋

𝑑𝑝𝑝> 0. Hence, the firm will set 𝑝𝑝 as high as possible, i.e., 𝑝𝑝

∗ = 𝑟. The firm’s profit

maximization problem then becomes:

max𝑝𝑏𝑟𝐹(𝑝𝑏 − 𝑟) + (𝑝𝑏 − 𝑐)[1 − 𝐹(𝑝𝑏 − 𝑟)]

s.t. 𝑝𝑏 − 𝑐 − 𝑟 ≥ 0

5 This is apart from the special case of Exponential 𝜃𝑏 because the hazard function of Exponential is just a horizontal straight

line. An increase or decrease in the parameter of the function shifts the function to the left or to the right on the Cartesian

plane. If the function is a horizontal straight line, shifting horizontally makes no difference.

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Lemma 2a (No piracy, No DRM; Mixed Bundling): An increase in 𝑟 increases 𝑝𝑝∗ = 𝑟 and 𝑝𝑏

∗ , but does not

affect the equilibrium Product demand 𝐹(𝑝𝑏∗ − 𝑟) or the equilibrium Bundle demand 1 − 𝐹(𝑝𝑏

∗ − 𝑟). As a

result, the firm’s equilibrium profit is increased.

Those buying the Product get zero surplus, while those buying the Bundle at least zero surplus.

The total consumer surplus is 𝐶𝑆∗ = −𝑥∗ + �̅�𝑏 − ∫ 𝐹(𝜃𝑏)�̅�𝑏

𝑥∗ 𝑑𝜃𝑏, where 𝑥∗ ≡ 𝑝𝑏∗ − 𝑟 is the consumer

who is indifferent between buying the Product and buying the Bundle.

Lemma 2b (No piracy, No DRM; Mixed Bundling): The equilibrium total consumer surplus is not affected by

an increase in r.

According to the proof of Lemma 2a, the position of the marginal consumer does not change

with r. With increasing 𝑟, those who buy the Product will continue to get zero surplus because the

monopolistic firm’s tendency to set the Product’s price to r. Interestingly, those buying the Bundle do

not enjoy an increase in surplus either. This is because the firm would be able to increase the price of

Bundle by an amount equal to the increase in 𝑟. This result contrasts that of Lemma 1a in the previous

subsection and highlights the superiority of MB in extracting surplus from a heterogeneous consumer

market.

Lemma 2b suggests that the relative reliance on the Product versus the Bundle in terms of sales

quantity does not change because of 𝑟. The increase in 𝑟 allows the firm to raise the prices of both the

Product and the Bundle. A raise in price in both goods does not alter the relative attractiveness of either

goods. Hence, the demand for the Bundle is not affected. The main driver of the increase in profitability

is the increase in prices rather than demand. We now summarize the results from the three bundling

strategies.

Proposition 1 (No piracy, No DRM):

(i). The firm’s optimal strategy is to offer both versions, i.e., {Product, Bundle}.

(ii). The equilibrium total consumer surplus is higher in PB than in MB.

This result is consistent with extant studies in that MB allows the firm to extract the most surplus

(Salinger, 1995; Schmalensee, 1984). Furthermore, if the cost of cloud services is sufficiently low, the

firm would prefer PB over PC. This result is consistent with Venkatesh and Mahajan (2009). In MB, the

Bundle’s price is higher than that in PB, but the Bundle demand is lower. Thus, the total consumer

surplus of Bundle buyers is lower in MB. Furthermore, the total consumer surplus of Product buyers is

zero in MB. Therefore, in this benchmark setting, the total consumer surplus in PB is higher than in MB.

The consumer surplus associated with PC is the lowest.

3.2 Model 2: With Piracy but No DRM

We now consider that piracy is present in the market. We assume that a pirated copy of the Product is of

the same quality as that of the legitimate Product. Since the auxiliary service component is not sold

separately, we assume that piracy of the Bundle is not possible (although consumers can still pirate the

Product component of the bundle). In the next subsection, DRM will impose a cost (negative value) for

the consumers who consume the pirated product.

We first consider the Pure Component strategy. Since the piracy cost is assumed to be less than

the price of the Product, all consumers will use the pirated software. In reality there could be ethical

users who refuse to use pirated software, but the point of this section is to show the worst-case scenario

that acts as a baseline for comparison. Hence, all consumers choose piracy. The firm’s profit is 0. The

total consumer surplus is 0 for legitimate users, while the total consumer surplus is 𝑟 for all users

(including both legitimate users and piracy users).

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In Pure Bundling strategy, an individual buying the Bundle must satisfy 𝑏 > 𝑝𝑏 − 𝑟 and 𝑏 >𝑝𝑏. The firm’s profit is 𝜋 = (𝑝𝑏 − 𝑐)[1 − 𝐹(𝑝𝑏)].

In the following analysis, we use subscripts to denote the bundling strategy (PC, PB or MB) of

the respective model as (1, 2, or 3). For example, 𝑝𝑏,𝑝𝑏,2 denote the Bundle price in pure bundling in

Model 2.

Lemma 3 (With piracy but No DRM; Pure Bundling): The presence of piracy decreases the optimal Bundle

price in PB, decreases the equilibrium Bundle demand, increases the equilibrium piracy demand and decreases

the equilibrium profit. If we include the welfare of pirates, the presence of piracy would increase the equilibrium

total consumer surplus. If we do not include the welfare of pirates, the presence of piracy would increase the

equilibrium total consumer surplus if and only if 𝑟𝐹(𝑝𝑏,𝑝𝑏,2∗ ) < 𝑝𝑏,𝑝𝑏,1

∗ − 𝑝𝑏,𝑝𝑏,2∗ + ∫ 𝐹(𝜃𝑏)

𝑝𝑏,𝑝𝑏,2∗

𝑝𝑏,𝑝𝑏,1∗ −𝑟

𝑑𝜃𝑏.

The surplus per consumer must increase because every legitimate user now enjoys a lower

Bundle price. The total consumer surplus seems to be decreased under some conditions simply because

the welfare of pirates is not included in the calculation.

In Mixed Bundling strategy, an individual buying the Bundle must satisfy 𝑏 > 𝑝𝑏 − 𝑟, 𝑏 >𝑝𝑏 − 𝑝𝑝 and 𝑏 > 𝑝𝑏. No individual will buy the Product. The firm’s profit is 𝜋 = (𝑝𝑏 − 𝑐)[1 − 𝐹(𝑝𝑏)]. Thus, the mixed bundling problem is now reduced to the pure bundling problem.

Lemma 4 (With Piracy and No DRM; Mixed Bundling): All Product buyers switch to piracy. The presence

of piracy decreases 𝑝𝑏∗ , but does not affect the equilibrium Bundle demand, decreases the equilibrium profit. If

we include the welfare of pirates, the presence of piracy would increase the equilibrium total consumer surplus.

If we do not include the welfare of pirates, the presence of piracy would increase the equilibrium total consumer

surplus if and only if 𝑟𝐹(𝑝𝑏,𝑚𝑏,2∗ ) < 𝑝𝑏,𝑚𝑏,1

∗ − 𝑝𝑏,𝑚𝑏,2∗ + ∫ 𝐹(𝜃𝑏)

𝑝𝑏,𝑚𝑏,2∗

𝑝𝑏,𝑚𝑏,1∗ −𝑟

𝑑𝜃𝑏.

With piracy, MB is reduced to PB. This leads to the same Bundle price 𝑝𝑏,𝑝𝑏,2∗ = 𝑝𝑏,𝑚𝑏,2

∗ . In other

words, the difference in Bundle price due to piracy is less for PB than for MB. This also means that the

left hand side of the inequalities in both lemmas are the same. On the right hand side, given that the

difference in price is less for PB than for MB, the right hand side of Lemma 3 is smaller than the right

hand side of Lemma 4. In other words, the condition is more easily satisfied under MB, meaning that the

presence of piracy is more likely to result in a greater increase in total consumer surplus under MB.

Proposition 2 (With Piracy but No DRM):

(i). Regardless of the selling strategy adopted, piracy negatively affects profitability. However, PB shows

greater resilience against the threat of piracy in terms of percentage change in profitability.

(ii). If we do not consider the surplus from pirates, the presence of piracy is more likely to increase the total

consumer surplus under MB.

We find that the firm will always be worse off regardless of the bundling strategy. This effect is

stronger under MB because the Product is in direct competition with the pirated product. Therefore, we

also see that the consumers are more likely to enjoy higher gains in surplus under MB. The presence of

piracy can be the “friend’ of the consumers. In terms of the benefit of piracy, previous studies have found

that piracy may allow the would-be consumer to sample the product and lead to greater number of

consumers buying the product (Chellappa & Shivendu, 2005).

3.3 Model 3: With Piracy and DRM

We assume the effectiveness of DRM in Product and that in Bundle is different. In Pure Component

strategy, we assume that that DRM increases the piracy cost to 𝜇. An individual buying the Product must

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satisfy 𝑟 > 𝑝𝑝 and 𝑝𝑝 ≤ 𝜇. It is obvious that the firm would set the Product price to 𝜇 and earn a profit

of 𝜇 from all consumers. The total consumer surplus is 𝑟 − 𝜇 . Therefore, 𝑝𝑝∗ = 𝜇 , 𝑑𝑝

∗ = 1, 𝜋∗ = 𝜇 ,

and 𝐶𝑆∗ = 𝑟 − 𝜇.

Lemma 5 (With piracy and DRM; Pure Component): In the presence of piracy, 𝜇 increases the optimal

Product price and the equilibrium profit for PC; it decreases the equilibrium total consumer surplus as well, if

pirates’ welfare is included. All consumers would choose the Product, i.e., no one would choose piracy.

Contrary to the case where DRM is not considered, the introduction of DRM allows the firm to

set a higher price when the cost imposed on the pirates are higher. At the same time, the firm sets the

price such that all consumers would choose the Product over the pirated product.

In Pure Bundling strategy, we assume that DRM in Bundle increases the piracy cost by 𝑡. An

individual buying the Bundle must satisfy 𝑏 > 𝑝𝑏 − 𝑟 and 𝑏 > 𝑝𝑏 − 𝑡.

Piracy is completely eliminated if t is sufficiently large such that t ≥ r. To allow for the analysis

of the more general case where piracy threat continues to exist, we assume 𝑡 ≤ 𝑟. Hence, the firm’s

total profit is 𝜋 = (𝑝𝑏 − 𝑐)[1 − 𝐹(𝑝𝑏 − 𝑡)]. The first order condition with respect to 𝑝𝑏 is 𝑑𝜋

𝑑𝑝𝑏= 1 −

𝐹(𝑝𝑏 − 𝑡) − (𝑝𝑏 − 𝑐)𝑓(𝑝𝑏 − 𝑡) = 0, or

𝑓(𝑝𝑏−𝑡)

1−𝐹(𝑝𝑏−𝑡)=

1

𝑝𝑏−𝑐. (3)

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Lemma 6: In the presence of piracy, 𝑡 increases 𝑝𝑏∗ , increases the equilibrium Bundle demand 1 − 𝐹(𝑝𝑏

∗ − 𝑡),

decreases the equilibrium piracy demand 𝐹(𝑝𝑏∗ − 𝑡), and increases the firm’s equilibrium profit. If we include

the welfare of pirates, 𝑡 decreases the equilibrium total consumer surplus. If we do not include the welfare of

pirates, an increase in 𝑡 would increase the equilibrium total consumer surplus if and only if

𝑟𝐹(𝑝𝑏,𝑝𝑏,2∗ ) − (𝑟 − 𝑡)𝐹(𝑝𝑏,𝑝𝑏,3

∗ − 𝑡) > 𝑝𝑏,𝑝𝑏,3∗ − 𝑝𝑏,𝑝𝑏,2

∗ + ∫ 𝐹(𝜃𝑏)𝑝𝑏,𝑝𝑏,2

𝑝𝑏,𝑝𝑏,3∗ −𝑡

𝑑𝜃𝑏.

Just as in the PC case, when the firm is able to impose higher costs on pirates with DRM, the

firm’s profit can be protected with a higher price. In the meantime, the firm can decease the piracy

demand; some consumers may choose to consume the Bundle legitimately. In general, increasing the

piracy cost (higher 𝑡) will increase 𝑝𝑏,𝑝𝑏,3∗ and increase the Bundle demand. In such a case, the condition

in Lemma 6 is more likely to be satisfied, in which the total consumer surplus is more likely to increase.

When MB is adopted, the Product is still available for sale as a standalone product. For this

standalone product, product keys are typically used. For the Bundle offered, the firm can use the regular

license check approach as described above. Thus, a person considering piracy can consider pirating the

product in the Bundle or the Product as a standalone good. The surplus from piracy is therefore 𝑟 − 𝑡 or

𝑟 − 𝜇, whichever is larger. Denote min[𝜇, 𝑡] as 𝜇′. An individual buying the Bundle must satisfy 𝑏 >𝑝𝑏 − 𝑟 and 𝑏 > 𝑝𝑏 − 𝜇′ . An individual buying the Product must satisfy 𝑟 > 𝑝𝑝 and 𝑝𝑝 < 𝜇′ . The

firm’s optimal Product price is 𝑝𝑝 = 𝜇′ . The firm’s profit is 𝜋 = 𝜇′𝐹(𝑝𝑏 − 𝜇′) + (𝑝𝑏 − 𝑐)[1 −

𝐹(𝑝𝑏 − 𝜇′)].

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Lemma 7 (With piracy and DRM; Mixed Bundling): An increase in 𝜇′ increases 𝑝𝑏∗ . An increase in 𝜇′ does

not affect the equilibrium Product demand 𝐹(𝑝𝑏∗ − 𝜇′) or the equilibrium Bundle demand 1 − 𝐹(𝑝𝑏

∗ − 𝜇′). The

equilibrium piracy demand is 0. 𝜇′ increases the equilibrium profit and decreases the equilibrium total

consumer surplus.

As with PC and PB, we see that the use of DRM will increase the firm’s profit more when a

greater piracy cost is imposed. Moreover, unlike with the PB case, the firm can remove piracy completely

under MB and the total consumer surplus will further decrease through stricter DRM. The resulting

decrease in the total consumer surplus can be easily verified since an increase in 𝜇′ increases 𝑝𝑏∗ , but

does not change 𝑝𝑏∗ − 𝜇′.

In the case of no DRM, we find that PB can never be better than the MB strategy. However, when

DRM is considered, the firm may make higher profit with PB.

Proposition 3 (With piracy and DRM): PB will be more profitable than MB if and only if

(𝑝𝑏,𝑝𝑏,3∗ − 𝑐)[1 − 𝐹(𝑝𝑏,𝑝𝑏,3

∗ − 𝑡)] > 𝜇′𝐹(𝑝𝑏,𝑚𝑏,3∗ − 𝜇′) + (𝑝𝑏,𝑚𝑏,3

∗ − 𝑐)[1 − 𝐹(𝑝𝑏,𝑚𝑏,3∗ − 𝜇′)].

A necessary condition is that 𝑡 > 𝜇.

Intuitively, when 𝑡 > 𝜇, 𝜇′ = 𝜇, piracy is easier in MB than in PB. The pirated software is a

close substitute to the Product. The competition effect forces the firm to set a low Product price. On the

other hand, a low Product price can cannibalize the Bundle. If the two effects are large, PB can be more

profitable than MB. Furthermore, a higher 𝑡 would lead to a higher 𝑝𝑏,𝑝𝑏,3∗ and lower 𝐹(𝑝𝑏,𝑝𝑏,3

∗ − 𝑡);

thus, the left hand side of the above inequality in Proposition 3 will be higher. The right hand side will

be the same since μ does not change. Therefore, the condition will be more easily satisfied. If 𝑡 does not

change, but 𝜇 decreases, 𝜇′ will be lower, 𝑝𝑏,𝑚𝑏,3∗ − 𝑐 will be lower and so the right hand side will be

lower, and this condition will also be more easily satisfied. In other words, the piracy curbing effect is

higher under PB, either through a higher 𝑡 or a lower 𝜇. Thus, an important implication of the analysis

in this subsection is that PB does not need to eliminate piracy completely for it to be the optimal bundling

strategy for the firm. If it makes piracy significantly more difficult or inconvenient, PB can be more

profitable than MB.

Lemma 8 (With piracy and DRM): MB is more affected by the effectiveness of DRM than PB.

Since the success of MB is more dependent on the effectiveness of DRM, the profitability

advantage of MB over PB decreases with increasing ease of piracy. Now, we compare the consumer

surplus between PB and MB.

Proposition 4 (With piracy and DRM): PB could be the optimal strategy from the perspectives of both firms

and consumers when

(i). Surplus from both legitimate users and pirates (𝑝𝑏,𝑚𝑏,3∗ − 𝜇′ − 𝑐)𝐹(𝑝𝑏,𝑚𝑏,3

∗ − 𝜇′) −

(𝑝𝑏,𝑝𝑏∗ − 𝑐)𝐹(𝑝𝑏,𝑝𝑏,3

∗ − 𝑡) > 𝑝𝑏,𝑚𝑏,3∗ − 𝑝𝑏,𝑝𝑏,3

∗ > ∫ 𝐹(𝜃𝑏)𝑝𝑏,𝑚𝑏,3

∗ −𝜇′

𝑝𝑏,𝑝𝑏,3∗ −𝑡

𝑑𝜃𝑏.

(ii). Surplus form legitimate users (𝑝𝑏,𝑚𝑏,3∗ − 𝜇′ − 𝑐)𝐹(𝑝𝑏,𝑚𝑏,3

∗ − 𝜇′) − (𝑝𝑏,𝑝𝑏,3∗ − 𝑐)𝐹(𝑝𝑏,𝑝𝑏,3

∗ − 𝑡) >

𝑝𝑏,𝑚𝑏,3∗ − 𝑝𝑏,𝑝𝑏,3

∗ > ∫ 𝐹(𝜃𝑏)𝑝𝑏,𝑚𝑏,3

∗ −𝜇′

𝑝𝑏,𝑝𝑏,3∗ −𝑡

𝑑𝜃𝑏 + 𝐾,where 𝐾 = (𝑟 − 𝑡)𝐹(𝑝𝑏,𝑝𝑏,3∗ − 𝑡) is the surplus from

piracy users in pure bundling.

In Proposition 3, we see that with strong competition and cannibalization effects, PB would be

the better strategy than MB for the firm. From the perspective of the consumers, due to the competition

effect, consumers enjoy a high surplus when buying the Product under MB. However, compared to PB,

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Bundle buyers get a lower surplus in MB because the Bundle price is higher in MB than in PB. Thus,

when the Bundle demand in PB is much higher than the Bundle demand in MB, and the Bundle price is

much lower in PB than in MB, the total consumer surplus will be higher in PB than in MB. Hence, the

situation where the total consumer surplus may be highest for PB can co-exist with pure bundling being

the firm’s optimal strategy. The intuition is similar when we consider the surplus from both legitimate

users and pirates or just the legitimate users. The only difference is that Proposition 4 (ii) is a more

stringent condition given we only consider the surplus from legitimate users.

4. Discussion and Conclusion

The emergence of Internet-enabled software services has added to the relevancy of studying the software

piracy problem together with the bundling strategy. Based on a general model, our work has sought to

contribute to two well-established but disconnected streams of research. Prior studies have found that

network externality can make pure bundling more profitable (Prasad et al., 2010). Moreover, pure

components may be optimal when the marginal cost is high (Venkatesh & Kamakura, 2003). In this

note, we have added another dimension to the discussion; i.e., with piracy and DRM considered, pure

bundling, instead of mixed bundling can be the optimal strategy. The results have generally confirmed

Gopal and Gupta’s (2010) finding that pure bundling can be a desirable strategy when piracy is

considered. However, we have derived our results based on comparisons to mixed bundling instead of

pure components, which is a more stringent requirement.

Our note contributes to the overall discussion on piracy and bundling of information goods. Pure

bundling strategy has been regarded to give firms with market power an unfair competitive advantage

(Kobayashi, 2005). With limited component options, consumers have argued that they are “forced” to

buy bundles with components that they may not need. For example, many Adobe users complained when

Adobe switched to a model of exclusively providing service based software subscription6 (Shankland,

2013). In our stylized setting, we provide an alternative perspective that, taking into consideration piracy

and DRM, pure bundling may be a desirable outcome for both the firms and the consumers. Moreover,

although we use software industry as the focus of our discussion, given that more and more products

have Internet-enabled extensions (such as toys, cars, home appliances), our results may be extended to

other products where the piracy or counterfeiting applies.

Motivated by the phenomenon of Internet-enabled service, the objective of this note has been to

study the intertwining effects that exist in software bundling and software piracy. With a view to

maintaining mathematical tractability, many potential relevant issues have been abstracted away in our

stylized models. For instance, considerations of industry competition, such as under a duopoly setting,

may provide additional interesting insights to the topic. Moreover, part of the excitement about the

Internet-enabled service phenomena is the potential to extend software functionalities to the massive

Internet-enabled collaborative environment, in which network externality may play an important role. It

could be interesting to consider these issues in future studies.

Acknowledgement

This work was partially supported by grants from National Natural Science Foundation of China (Grant

71801014) and Beijing Social Science Foundation (Grant 17GLC069).

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