Comparing Compliance Behaviour of Students and Farmers. An Extra-laboratory Experiment in the Context of Agri-environmental Nudges in Germany

Increasing popularity of economic experiments for policy impact analysis has led to an on-going debate about the suitability of students to substitute professionals as experimental subjects. To date, subject pool effects in agricultural and resource economics experiments have not been sufficiently studied. In order to identify differences and similarities between students and non-students, we carry out an experiment in the form of a multi-period business management game that is adapted to an agri-environmental context. We compare the compliance behaviour of German agricultural students and German farmers with regard to water protection rules and analyse their responses to two different green nudge interventions. The experimental results reveal that the direction of the response to the policy treatments is similar. Even unexpected behaviour could be reproduced by the student sample. Nevertheless, the magnitude of the treatment effects differed between the two samples. This implies that experimenters in the field of agricultural and resource economics could use the subject pool of students to analyse the direction of nudge policies. If predictions should be made about the magnitude effects, we suggest using a professional subject pool.     

Capital asset pricing model in Portugal: Evidence from fractal regressions

We examine risk profiles of the Portuguese stock market index component stocks using a novel approach to the classical capital asset pricing model (CAPM). Specifically, we estimate the CAPM via fractal regressions that allow studying the marginal effects at selected scales. In this way, we can reveal whether the risk is perceived differently by market participants with different investment horizons. Apart from the analysis itself, we provide new statistical insights into the issue of separating and comparing the scale-specific effects with statistical validity. We find several stocks deviating from an expected risk perception homogeneity across investment horizons. This is true for both analysed periods, i.e. before and after the global financial crisis. There are also several stocks that changed their relationship to the market portfolio in between, which has strong implications for possible portfolio construction. The proposed methodology is not limited to financial topics but can be used in any discipline where the scale-specific marginal effects might be of interest.     

Virtually No Effect? Different Uses of Classroom Computers and their Effect on Student Achievement

Most studies find little to no effect of classroom computers on student achievement. We suggest that this null effect may combine positive effects of computer uses without equivalently effective alternative traditional teaching practices and negative effects of uses that substitute more effective teaching practices. Our correlated random effects models exploit within‐student between‐subject variation in different computer uses in the international TIMSS test. We find positive effects of using computers to look up information and negative effects of using computers to practice skills, resulting in overall null effects. Effects are larger for students with high socioeconomic status and mostly confined to developed countries.     

The Structure of Problem Structuring Conversations: A Boundary Games Approach

One of the questions associated with facilitated problem structuring is how the micro level of actors’ multimodal communications, contributes to the emergence of a macro level, framing the possibilities for action in a workshop. This paper shows a way to study this macro level, building the visualization of the conversations’ structure starting from a boundary games theory micro analysis of the interactions. Our empirical evidence comes from following a group of academic consultants working to define a value proposition for their activity. We focus on analyzing two out of nine workshops that were felt diametrically opposite in terms of facilitation and achievements. Moving from the micro towards an upward level, three configurations building the structure are identified—shifting, branching and converging. The work carried out allows us to: (1) visualize the structure of conversations in a problem structuring context, (2) highlight the role of multimodal communications in building the conversations and (3) construct an interpretation bridging the micro and macro readings of a workshop. This knowledge is useful for facilitators guiding the dynamic of a workshop and for researchers looking forward to understanding how micro level interactions build higher levels of the social phenomenon of intervention.     

Public debt and economic growth in Spain, 1851–2013

In this paper we investigate the long-run relationship between public debt and economic growth in the Spanish economy for the period 1851–2013. We develop a cliometric analysis of the debt–growth nexus using novel time series methods. We find some support for a negative relationship between both variables, but no clear evidence of a debt threshold. The estimated long-run elasticity in a one-break model shows a tendency to decrease over time from a nonsignificant 0.011 to a ?0.070, indicating that a 10 percentage increase in the public debt-to-GDP ratio is associated with 0.70 percentage points lower real economic growth. Indeed, we find for the first subsample (1851–1939) either “decoupling” or “saturation,” while in the second subsample (1940–2000) the long-run elasticity coefficient becomes negative and significant. When we extend our analysis up to 2013, we find a break in 1971 coinciding with the twilight of Franco’s dictatorship and the Spanish transition to democracy.     

Structural comparisons of networks and model-based detection of small-worldness

In this paper, we consider the problem of assessing the “level of small-worldness” of a graph and of detecting small-worldness features in real networks. After discussing the limitations of classical approaches, based on the computation of network indicators, we propose a new procedure, which involves the comparison of network structures at different “observation scales”. This allows small-world features to be caught, even if “hidden” deeply into the network structure. Applications of the procedure to both simulated and real data show the effectiveness of the proposal, also in distinguishing between different small-world models and in detecting emerging small-worldness in dynamical networks.     

Measuring and forecasting mobile game app engagement

Monetization strategies in the large and strongly growing mobile app space must go beyond traditional purchase revenue as most mobile apps are now free to download. One key marketing innovation allows mobile app publishers to monetize ongoing engagement — in-app advertising.We study ongoing user engagement with a mobile app after the initial download decision using the $40 billion mobile gaming industry as an example. Our study investigates and forecasts user engagement after the initial download aiming to help publishers to monetize their engagement via in-app advertising. We leverage a novel dataset containing user-level engagement for 193 mobile games and propose a hierarchical Poisson model on a mobile-game level. We find significant usage heterogeneity across the mobile games studied and generate forecasts publishers can use when trying to monetize engagement via pre-sold contracts.     

Consumer Law and Policy in Ghana

This paper presents a picture of the landscape of consumer law and policy in Ghana and reviews the scope of protection of consumer interests with specific regard to product safety and liability, consumer sales, and telecommunication services. It assesses the legislative and policy framework on consumer contracts, product safety, and unfair commercial practices; discusses the role of national agencies in enforcing safety standards; and highlights some critical consumer issues in telecommunications service delivery. The paper examines the regulatory framework on other consumer issues such as advertising, labelling, and marketing of consumer products; terms and conditions of consumer contracts; and after sales services including the enforcement of guarantees, warranties, refund, and return policies. The paper also discusses the extent of external influence on the development of consumer law and policy in Ghana and reviews the level of interaction with other legal systems and supranational bodies in the three focal areas. The contribution also explores areas of Ghana’s consumer protection framework which could benefit from guidance from the EU transnational model on consumer protection and makes recommendations for the enhancement of the emerging legislative and policy regime on consumer protection in Ghana.     

Impact of Online Customer Reviews on Sales Outcomes: An Empirical Study Based on Prospect Theory

This study examines the influence of the valence of online customer reviews on sales outcomes based on prospect theory. Numerous studies have revealed the importance of customer reviews in online marketing. However, only few studies have explored the impact of online customer reviews on sales outcomes in the dynamic process. Prior studies in behavioral economics literature have indicated that people differently value gains and losses and that losses have more emotional impact than an equivalent amount of gains. This study verifies whether prospect theory applies to the relation between online customer reviews and sales outcomes. Relevant data were collected from Amazon.co.jp, and three statistical models were employed to investigate the relation between the two factors. Major findings confirm that negative customer reviews considerably impact online sales than positive reviews. Furthermore, the findings indicate that the marginal effects of positive and negative reviews decrease with the increase in their volume. The results of this study will enable marketers to compare the relative sales effects of different types of customer reviews and improve the effectiveness of customer service management.