Bundling, information and two-sided platform competition – Job Market Paper

authorThe following job market paper summary was contributed by Keke Sun (IDEA). Keke is a job market candidate at UAB. Her research interests include Industrial Organization, Venture Capital Markets and Innovation.

Two-sided markets are economic platforms that connect two interdependent groups of users together and enable certain interactions between these two groups of users. The main characteristic of two-sided markets is the indirect network externalities, meaning that one group user’s benefits of joining one platform depends on the number of users of the other group on the same platform. My job market paper studies the impact of pure bundling and the level of consumer information on two-sided platform competition.

The Story

This paper is motivated by the casual observations from the smartphone operating system industry. The operating system (OS) platform connects consumer and application developers, the major competitors are Android by Google and iOS by Apple. Apple also has its amazing in-house handset, iPhone, it bundles the handset with the OS platform.


The Main Results

The leverage theory has established that, in standard one-sided market, if a firm can commit to pure bundling, when consumers have homogeneous valuation of the bundling product, pure bundling reduces equilibrium profits for all firms. Therefore, bundling is usually adopted to deter entry or lead to foreclosure (see Whinston (1990) and Carlton and Waldman (2002) ). However, in a two-sided market, if a platform could commit to aggressive pricing on one side and gain a larger market share. Hence, it becomes more valuable to the users on the other side. I show that, in the presence of asymmetric network externalities, when consumers have homogeneous valuation of the bundling handset, bundling may emerge as a profitable strategy when platforms engage in “divide-and-conquer” strategy: subsidizing the low externality side (consumers) for participation and making profits on the high-externality side (developers). That is, when the benefits of attracting one extra consumer are very strong, committing to aggressive pricing can be profitable without inducing the exit of the rival.

This paper also studies the impact of the level of consumer information on platform competition and the emergence of the bundling decision. Most literature on two-sided markets assumes that all agents have full information about prices and others’ preferences; therefore, can perfectly predict others’ participation decision (see Rochet and Tirole (2003), Caillaud and Jullien (2003), and Armstrong (2006) etc.). Following Hagiu and Halaburda (2014), I use the setting of a hybrid scenario in which some consumers are informed about developer subscription prices and hold responsive expectations about developer participation, while the remaining consumers are uninformed and hold passive expectations. This setting should be a good fit of a situation where information may be less than perfect for some users on different sides of the platform. For instance, some consumers don’t know how much Apple or Google charges the developers for listing applications. Information intensifies price competition with or without bundling. Bundling is more effective in stimulating consumer demand the larger proportion of informed consumers, but bundling is less likely to emerge as the fraction of informed consumers increases.

Strategy and Policy Implications

From a strategy perspective, this paper shows that both platforms have incentives to affect consumers’ knowledge regarding developer subscription prices. Without bundling, both platforms have incentives to withhold the information because consumer information intensifies price competition on both sides. However, when bundling does occur, the two platforms may have different attitudes towards consumer information. The bundling platform prefers a high level of consumer information because bundling is more effective to stimulate consumer demand. The competing platform wishes to withhold the information as it gets worse off as the level of consumer information increases. This paper also shows that when the network externalities are strong, it is more profitable for the platforms to be more aggressive.

From a public policy perspective, this paper provides recommendations concern bundling and information disclosure. Due to the existence of (positive) network externalities, consumer surplus increases with the number of developers on the same platform. Bundling does not only affect consumer subscription prices, but also affects the perceived quality of platforms as it affects developer participation. It has shown that pure bundling improves consumer welfare mainly because it offers a lower subscription price and more application variety to the majority of consumers. For the same reason, even when bundling implements second-degree price discrimination, bundling still improves consumer welfare. Also, information disclosure unambiguously improves consumer surplus by lowering subscription prices on both sides of the platform and improving developer participation. Thus, information disclosure should be encouraged or mandated for consumer’s sake.

Paper abstract and download available on Keke’s website

The Mission: Human Capital and the Persistence of Fortune – Job Market Paper

Job market paper Felipe Valencia ’15 (GPEFM – UPF and Barcelona GSE)

Felipe ValenciaThe following job market paper summary was contributed by Felipe Valencia (GPEFM – UPF and Barcelona GSE).

**Update: This paper has now been published in the Quarterly Journal of Economics and featured in the The Washington Post!**

The importance of history in economic development is well-established (Nunn 2009; Spolaore and Wacziarg 2013), but less is known about the specific channels of transmission which drive this persistence in outcomes. Dell (2010) stresses the negative effect of the mita in Latin America, and Nunn and Wantchekon (2011) document the adverse impact of African slavery through decreased trust. But did other colonial arrangements lead to positive outcomes in the long run?

I address this question in my Job Market Paper by analyzing the long-term economic consequences of European missionary activity in South America. I focus on missions founded by the Jesuit Order in the Guarani lands during the seventeenth and eighteenth centuries, in modern-day Argentina, Brazil and Paraguay. This case is unique in that Jesuits were expelled from the Americas in 1767 –following European “Great Power” politics— precluding any continuation effect. While religious conversion was the official aim of the missions, they also increased human capital formation by schooling children and training adults in various crafts. My research question is whether such a one-off historical human capital intervention can have long-lasting effects.

The author at the site of one of the Jesuit missions on Guarani lands in South America.


To disentangle the national institutional effects from the human capital shock the missions supplied, I use within country variation in missionary activity in three different countries:

Note: The map shows the exact location of the Guarani Jesuit Missions (black crosses) with district level boundaries for Argentina, Brazil and Paraguay.


The area under consideration was populated by a single semi-nomadic indigenous tribe, so I can abstract from the direct effects of different pre-colonial tribes (Maloney and Valencia 2012; Michalopoulos and Papaioannou, 2013). The Guarani area also has similar geographic and weather characteristics, though I control for these variables in the estimation.

Key Findings

Using municipal level data for five states (Corrientes and Misiones in Argentina, Rio Grande do Sul in Brazil, and Itapúa and Misiones in Paraguay), I find substantial positive effects of Jesuit missions on human capital and income, 250 years after the missionaries were expelled. In municipalities where Jesuits carried out their apostolic efforts, median years of schooling and literacy levels remain higher by 10-15%. These differences in educational attainment have also translated into higher modern per capita incomes of nearly 10%. I then analyze potential cultural mechanisms that can drive the results. To do so I conduct a household survey and lab-in-the-field experiments in Southern Paraguay. I find that respondents in missionary areas have higher non-cognitive abilities and exhibit more pro-social behavior.


Even though I use country and state-fixed effects as well as weather and geographic controls, Jesuit missionaries might have chosen favorable locations beyond such observable factors. Hence the positive effects might be due to this initial choice and not to the missionary treatment per se.

To address the potential endogeneity of missionary placement, I conduct two empirical tests. The first one is a placebo that looks at missions that were initially founded by the Jesuits but were abandoned early on (before 1659). I can thereby compare places that were initially picked by missionaries with those that actually received the missionary treatment. I find no effect for such “placebo” missions, which suggests that what mattered in the long run is what the missionaries did and not where they first settled.

Second, I conduct a comparison with the neighboring Guarani Franciscan Missions. The comparison is relevant as both orders wanted to convert souls to Christianity, but Jesuits emphasized education and technical training in their conversion. Contrary to the Jesuit case, I find no positive long-term impact on either education or income for Franciscan Guarani Missions. This suggests that the income differences I estimate are likely to be driven by the human capital gains the Jesuits provided.

In addition, I employ an IV strategy, where I use as instruments the distance from early exploration routes and distance to Asuncion. Distance from the exploration routes of Mendoza (1535-1537) and Cabeza de Vaca (1541-1542) serves as a proxy for the isolation of the Jesuit missions (in the spirit of Duranton et al. 2014). Asuncion, in turn, served as a base for missionary exploration during the foundational period, but became less relevant for Rio Grande do Sul after the Treaty of Madrid (1750) transferred this territory to Portuguese hands. For this reason and to avoid the direct capital –and Spanish Empire—effects, I use this variable only for the Brazilian subsample of my data (as in Becker and Woessmann 2009; Dittmar 2011). The first-stage results are strongly significant throughout (with F-statistics well above 10), and the second-stage coefficients for literacy and income retain their sign and significance –appearing slightly larger—in the IV specifications.

Extensions and Mechanisms

To complete the empirical analysis, I examine cultural outcomes and specific mechanisms that can sustain the transmission of human capital from the missionary period to the present. I find that respondents in missionary areas possess superior non-cognitive abilities, as proxied by higher “Locus of Control” scores (Heckman et al., 2006). Using standard experiments from the behavioral literature, I find that respondents in missionary areas exhibit greater altruism, more positive reciprocity, less risk seeking and more honest behavior. I use priming techniques to further investigate whether these effects are the result of greater religiosity –which appears not to be the case.

In terms of mechanisms, my results indicate that municipalities closer to historic missions have changed the sectoral composition of employment, moving away from agriculture and towards manufacturing and services (consistent with Botticini and Eckstein, 2012). In particular, I document that these places still produce more handicrafts such as embroidery, a skill introduced by the Jesuits. People closer to former Jesuit missions also seem to participate more in the labor force and work more hours, consistent with Weber (1978). I also find that indigenous knowledge —of traditional medicine and myths—was transmitted more from generation to generation in the Jesuit areas. Unsurprisingly, given their acquired skills, I find that indigenous inhabitants from missionary areas were differentially assimilated into colonial and modern societies. Additional robustness tests suggest that the results are not driven by migration, urbanization or tourism.

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Heterogeneous Inputs, Human Resource Management and Productivity Spillovers: What Do Poultry Farm Workers Have to Say? – Job Market Paper

authorThe following job market paper summary was contributed by Francesco Amodio (Economics ’10 and GPEFM). Francesco is a job market candidate at UPF. He will be available for interviews at the SAEe (Palma de Mallorca, December 11-13) and ASSA (Boston, January 3-5) meetings.


Management matters. Differences in management practices can explain a considerable amount of variation in firms’ productivity and performance, both across and within sectors and countries (Bloom and Van Reenen 2007, 2010, 2011). Several studies have shown how human resource management and incentive schemes may affect overall productivity by making the effort choices of coworkers interdependent (Bandiera, Barankay and Rasul 2005, 2007, 2009). In more complex settings, however, workforce management features may interact with production arrangements and jointly determine the overall result of the organization. Understanding the nature of this interplay is of primary importance in the adoption and implementation of productivity-enhancing management practices.

In my job market paper, coauthored with Miguel A. Martinez-Carrasco, we shed light on these issues by focusing on settings where workers produce output by combining their own effort with inputs of heterogeneous quality. This is a common feature of workplaces around the world. For instance, in Bangladeshi garment factories, the characteristics of raw textiles used as inputs affect the productivity of workers. Similarly, the purity level of chemicals affects the productivity of researchers in biological research labs.

Now, suppose we pick a worker and endow her with higher quality inputs, thus increasing her productivity. What happens to the productivity of coworkers around her? Do they exert more effort, or do they shirk? How do human resource management features shape their response?

The setting

In order to answer these questions, we collected data from an egg production plant in Peru. Production is carried out in production units located one next to the other in several sheds. In each production unit, a single worker is assigned as input a batch of laying hens. Workers’ main tasks are to feed the hens, to maintain and clean the facilities, and to collect the eggs. The characteristics of the hens and worker’s effort jointly determine productivity, as measured by the daily number of collected eggs. Figure 1 shows the picture of one shed hosting four production units. Notice how workers in neighboring production units can easily interact and observe each other.


The specific features and logistics of this setting generate the quasi-experiment we need in order to answer the questions of interest. All hens within a given batch have very similar characteristics. When reaching their productive age, they are moved to one production unit and assigned to the corresponding single worker who operates the unit. After approximately 16 months, they reach the end of their productive age and are discarded altogether. The age of hens in the batch exogenously shifts productivity. Indeed, Figure 2 shows the reversed U-shaped relationship that exists between hens’ age and productivity. Perhaps more importantly, the timing of batch replacement varies across production units, generating quasi-random variation in the age of hens assigned to workers.1 We can thus exploit these differences to credibly identify the causal effect of an increase in coworkers’ productivity – as exogenously shifted by coworkers’ hens age – on own productivity, conditional on own hens’ age.


Main Results

We find evidence of negative productivity spillovers. The same worker, handling hens of the same age, is significantly less productive when coworkers in neighboring production units are more productive, with variation in the latter being induced by changes in the age of their own hens. This finding is pictured in Figure 3, which shows that a U-shaped relationship exists between own productivity and coworkers’ hens age. In other words, workers exert less effort and decrease their productivity when coworkers are assigned higher quality inputs.


We also find similar negative effects on output quality, as measured by the fraction of broken and dirty eggs collected over the total number of eggs. Furthermore, we find no effect of an increase in the productivity of coworkers located in non-neighboring production units or in different sheds, suggesting that workers only respond to observed changes in coworkers’ productivity.

The role of HR

Why do workers exert less effort when coworkers’ productivity increases? Our hypothesis is that the way the management processes information on workers’ productivity in evaluating them and taking employment termination decisions generates free ride issues among coworkers. When observed productivity is only a noisy signal of workers’ exerted effort, the management combines available signals and best guesses the level of effort exerted by the worker. Even when observable input characteristics can be netted out, individual signals are still imperfect, and possibly excessively costly to process. The management thus attaches a positive weight to aggregate or average productivity in evaluating a single worker. As a result, workers free ride on each other.

In order to test for this hypothesis, we collected employee turnover data from the same firm. As expected, we find that the likelihood of employment termination is lower the more productive the worker is. More importantly, being next to highly productive workers improves a given worker’s evaluation and diminishes her marginal returns from effort, yielding negative productivity spillovers.

We also find that providing incentives to workers counteracts their tendency to free ride. First, we find no effect of coworkers’ productivity when workers are exposed to piece-rate pay. Second, we collected data on the friendship and social relationship among workers, and find again no effect of coworkers’ productivity when a given worker recognizes any of her coworkers as friends. We interpret this as further evidence that the main result of a negative effect of coworkers’ productivity indeed captures free riding issues, mitigated by the presence of social relationships.


Our focus on production inputs and their allocation to working peers represents the main innovation with respect to the previous literature on human resource management and incentives at the workplace. In our case study, the allocation of inputs of heterogeneous quality among workers triggers free riding and negative productivity spillovers among them, generated by the workers’ evaluation and termination policies implemented at the firm.

The analysis of more complex production settings reveals the existence of intriguing patterns of interplay between production arrangements and human resource management practices. Our plan for the next future is to proceed further along this line of inquiry. In a companion paper still work in progress, we investigate both theoretically and empirically how workers influence each other in their choice of inputs while updating information on the productivity of the latter from own and coworkers’ experience.

1 Grouping all observations belonging to the same shed and week and taking residuals, we show that the age of hens assigned to coworkers is orthogonal to the age of own hens. We test this hypothesis in several different ways, addressing the issues arising when estimating within-group correlation among peers’ characteristics (Guryan, Kroft, and Notowidigdo 2009; Caeyers 2014). We cannot reject the hypothesis of zero correlation in all cases.