Browsing by Author "Ferreira, Pedro"
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- Broadband in schools: does it help or hurt student performance?Publication . Belo, Rodrigo; Ferreira, Pedro; Telang, RahulThis paper provides empirical evidence on the effects of broadband Internet usage in schools on student performance in terms of national exams scores. We use a rich panel of data that has information on test scores, as well as broadband usage for all schools in Portugal, allowing us to control for school-specific effects. Additionally we use an instrument to account for possible unobserved time-varying effects. For 9th grade students, our estimates indicate that a higher use of broadband Internet is detrimental for students' test scores, despite this effect seeming to be wearing off with time. We find that the adverse effect tends to be reinforced for boys and weakened for girls, compared to the pooled estimates. We also find that schools with worse performance right before the introduction of broadband Internet in schools suffered the most. Our results suggest that introduction of broadband Internet in schools is not enough to improve students' performance. Broadband deployment in schools needs to be accompanied by complementary measures that support the use of the technology in productive ways.
- Challenges on the path to regular online shopping: e-grocery sector - UKPublication . Ferreira, PedroThis paper attempts to uncover significant economic and non-economic demand-side variables, which are driving and hindering B2C (Business to Consumer) e-commerce learning. It investigates the perceptions of individual customers on the path towards a specific regular type of online-buying: E-Grocery shopping (EGS). The analysis and result display is based on an e-customer learning framework, consisting of clear crucial steps arranged in a tree decision format which illustrate decisions faced by customers as they evolve from non-Internet user to regular Egrocery shopper. This framework was applied via mail survey to a sample of 2036 households in England. Results (through regression and mean testing) are pointing at two critical barriers on the path to E-grocery: · One network specific: National Digital Divide creating an important cost for potential users. · One sector specific: E-grocery is a sector plagued by non-friendly sites together with deficient logistics. With this cost structure, the niche market for e-grocers seems to be a reality, confirming Pfeffers [3] view. Income proves to be a key variable behind e-shopping learning, generating a very high and cumulative premium tag on e-grocery. Also interesting, is the fact that grocery shopping still preserves its feminine connotation online.
- Controlling digital piracy via domain name system blocks: a natural experimentPublication . Reis, Filipa; Matos, Miguel Godinho de; Ferreira, PedroWe study the impact of batch DNS filtering of copyright-infringing websites, a novel administrative-based process that does not require judicial involvement. In partnership with a large telecommunication provider, we measure the impact of this intervention on piracy activity and the legal alternatives integrated into households' media subscription bundles, an aspect largely unexplored in prior literature. We find a significant reduction in Internet traffic, which proxies piracy activity. However, we do not observe statistically significant changes in the consumption of the legal alternatives under consideration, only a slight increase in TV viewership. To further understand these outcomes, we examine the heterogeneity of these results based on households' pre-block usage intensity of digital piracy and demographic characteristics. Our work contributes to the literature on the effectiveness of piracy control strategies and informs policy makers and industry practitioners about the benefits and limitations of DNS-based website blocking.
- Culling the herd: using real-world randomized experiments to measure social bias with known costly goodsPublication . Matos, Miguel Godinho de; Ferreira, Pedro; Smith, Michael D.; Telang, RahulPeer ratings have become increasingly important sources of product information, particularly in markets for information goods. However, in spite of the increasing prevalence of this information, there are relatively few academic studies that analyze the impact of peer ratings on consumers transacting in real-world marketplaces. In this paper, we partner with a major telecommunications company to analyze the impact of peer ratings in a real-world video-on-demand market where consumer participation is organic and where movies are costly and well known to consumers. After experimentally changing the initial conditions of product information displayed to consumers, we find that, consistent with the prior literature, peer ratings influence consumer behavior independently from underlying product quality. However, we also find that, in contrast to the prior literature, there is little evidence of long-term bias as a result of herding effects, at least in our setting. Specifically, when movies are artificially promoted or demoted in peer rating lists, subsequent reviews cause them to return to their true quality position relatively quickly. One explanation for this difference is that consumers in our empirical setting likely had more outside information about the true quality of the products they were evaluating than did consumers in the studies reported in prior literature. Although tentative, this explanation suggests that in real-world marketplaces where consumers have sufficient access to outside information about true product quality, peer ratings may be more robust to herding effects and thus provide more reliable signals of true product quality than previously thought.
- Cultural and linguistic adaptation and validation of the Morse Fall ScalePublication . Costa-Dias, Maria; Ferreira, Pedro; Oliveira, AlexandreBackground: Patients’ falls are the most commonly reported safety incident in hospitals. Falls have clear consequences on the patient, family and health professionals. Prevention interventions should be prescribed based on each patient’s fall risk assessment. This assessment may be performed using scales such as the Morse Fall Scale (MFS). Despite being used in several hospitals, this scale was never formally validated until now. Objectives: To assess the degree of reproducibility of the MFS in hospital settings and examine its validity through correlations with other measuring instruments. Methodology: The study was conducted in two hospitals in the Lisbon area using a sample composed of 120 nurses, who applied the MFS to 200 patients. Each patient was assessed three times with the MFS by three different nurses. A total of 600 assessments were performed. Results: The Portuguese version is semantically and culturally equivalent to the original, with good reliability (intraclass correlation coefficient of 0.838 and interobserver agreement between 0.615 and 0.964, assessed using the mean kappa coefficient) and satisfactory convergent validity. Conclusion: The Portuguese version is recommended for use in hospital context.
- Fall risk assessment toolsPublication . Costa-Dias, Maria; Ferreira, PedroBackground: Accidental falls remain the most reported incidents in hospital settings. This is a quality and safety issue for the patient which needs to be addressed by the hospital organisation. Nurses need to assess the risk of falling using scales. However, nurses are sometimes unsure of what is the most appropriate tool. Objective: To provide information on the two most commonly used scales for assessing the risk of falling, i.e., the St Thomas’s Risk Assessment Tool in Falling Elderly Inpatients (STRATIFY) and the Morse Fall Scale (MFS). Main topics for analysis: The fall risk assessment tools which were the subject of more systematic reviews and prospective validation in two or more cohorts, with appropriate tests to predict their validity, were analysed. The review concluded that both scales identify patients who are at risk of falling based on their intrinsic or clinical characteristics. Conclusion: Hospitals should use scales which have already been developed and tested for data comparison. These scales should be culturally and linguistically adapted, and validated for the Portuguese language.
- Peer influence in the diffusion of iPhone 3G over a large social networkPublication . Matos, Miguel Godinho de; Ferreira, Pedro; Krackhardt, DavidIn this paper, we study the effect of peer influence in the diffusion of the iPhone 3G across a number of communities sampled from a large dataset provided by a major European Mobile carrier in one country. We identify tight communities of users in which peer influence may play a role and use instrumental variables to control for potential correlation between unobserved subscriber heterogeneity and friends' adoption. We provide evidence that the propensity of a subscriber to adopt increases with the percentage of friends who have already adopted. During a period of 11 months, we estimate that 14 percent of iPhone 3Gs sold by this carrier were due to peer influence. This result is obtained after controlling for social clustering, gender, previous adoption of mobile Internet data plans, ownership of technologically advanced handsets, and heterogeneity in the regions where subscribers move during the day and spend most of their evenings. This result remains qualitatively unchanged when we control for changes over time in the structure of the social network. We provide results from several policy experiments showing that, with this level of effect of peer influence, the carrier would have hardly benefitted from using traditional marketing strategies to seed the iPhone 3G to benefit from viral marketing.
- Target the ego or target the group: evidence from a randomized experiment in proactive churn managementPublication . Matos, Miguel Godinho de; Ferreira, Pedro; Belo, RodrigoWe propose a new strategy for proactive churn management that actively uses social network information to help retain consumers. We collaborate with a major telecommunications provider to design, deploy, and analyze the outcomes of a randomized control trial at the household level to evaluate the effectiveness of this strategy. A random subset of likely churners were selected to be called by the firm. We also randomly selected whether their friends would be called. We find that listing likely churners to be called reduced their propensity to churn by 1.9 percentage points from a baseline of 17.2%. When their friends were also listed to be called, their likelihood of churn reduced an additional 1.3 percentage points. The client lifetime value of likely churners increased 2.1% with traditional proactive churn management, and this statistic becomes 6.4% when their friends were also listed to be called by the firm. We show that, in our setting, likely churners receive a signal from their friends that reduces churn among the former. We also discuss how this signal may trigger mechanisms akin to both financial comparisons and conformity that may explain our findings.
- The effect of binge-watching on the subscription of video on demand: results from randomized experimentsPublication . Matos, Miguel Godinho de; Ferreira, PedroWe analyze the outcomes of two randomized field experiments to study the effect of binge-watching on subscription to video on demand. In both cases, we offered access to subscription VoD (SVoD) to a random set of households for several weeks and used another random set of households as a control group. In both cases, we find that the households that binge-watch TV shows are less likely to pay for SVoD after these free trials. Our results suggest that binge-watchers deplete the content of interest to them very quickly, which reduces their short-term willingness to pay for SVoD. We also show that recommendation reminders aimed at widening the content preferences of households offset the negative effect of binge-watching and lessen the concerns of binge-watchers with lack of content refresh. We discuss that these recommendation reminders may help content providers manage supply costs, which may otherwise become prohibitive with frequent updates to SVoD catalogs.
- The effect of friends’ churn on consumer behavior in mobile networksPublication . Ferreira, Pedro; Telang, Rahul; Matos, Miguel Godinho deWe study how consumers decide which tariff plan to choose and whether to churn when their friends churn in the mobile industry. We develop a theoretical model showing conditions under which users remain with their carrier and conditions under which they churn when their friends do. We then use a large and rich anonymized longitudinal panel of call detailed records to characterize the consumers’ path to death with unprecedented level of detail. We explore the structure of the network inferred from these data to derive instruments for friends’ churn, which is typically endogenous in network settings. This allows us to econometrically identify the effect of peer influence in our setting. On average, we find that each additional friend that churns increases the monthly churn rate by 0.06 percent. The observed monthly churn rate across our dataset is 2.15 percent. We also find that firms introducing the pre-paid tariff plans that charge the same price to call users inside and outside the carrier help retain consumers that would otherwise churn. In our setting, without this tariff plan the monthly churn rate could have been as high as 8.09 percent. We perform a number of robustness checks, in particular to how we define friends in the social graph, and show that our results remain unchanged. Our paper shows that the traditional definition of customer lifetime value underestimates the value of consumers and, in particular, that of consumers with more friends due to the effect of contagious churn and, therefore, managers should actively take into account the structure of the social network when prioritizing whom to target during retention campaigns.