Predicting mobile advertising response using consumer colocation networks

Building on results from economics and consumer behavior, the authors theorize that consumers' movement patterns are informative of their product preferences, and this study proposes that marketers monetize this information using dynamic networks that capture colocation events (when consumers appear at the same place at approximately the same time). To support this theory, the authors study mobile advertising response in a panel of 217 subscribers. The data set spans three months during which participants were sent mobile coupons from retailers in various product categories through a smartphone application. The data contain coupon conversions, demographic and psychographic information, and information on the hourly GPS location of participants and on their social ties in the form of referrals. The authors find a significant positive relationship between colocated consumers' response to coupons in the same product category. In addition, they show that incorporating consumers' location information can increase the accuracy of predicting the most likely conversions by 19%. These findings have important practical implications for marketers engaging in the fast-growing location-based mobile advertising industry

Gene expression drives the evolution of dominance.

Dominance is a fundamental concept in molecular genetics and has implications for understanding patterns of genetic variation, evolution, and complex traits. However, despite its importance, the degree of dominance in natural populations is poorly quantified. Here, we leverage multiple mating systems in natural populations of Arabidopsis to co-estimate the distribution of fitness effects and dominance coefficients of new amino acid changing mutations. We find that more deleterious mutations are more likely to be recessive than less deleterious mutations. Further, this pattern holds across gene categories, but varies with the connectivity and expression patterns of genes. Our work argues that dominance arises as a consequence of the functional importance of genes and their optimal expression levels

Spatial clustering and nonlinearities in the location of multinational firms

We propose a semiparametric geoadditive negative binomial model of industrial location which allows to simultaneously address some important methodological issues, such as spatial clustering and nonlinearities, which have been only partly addressed in previous studies. We apply this model to analyze location determinants of inward greenfield investments occurred over the 2003-2007 period in 249 European regions. The inclusion of a geoadditive component (a smooth spatial trend surface) allows to control for omitted variables which induce spatial clustering, and suggests that such unobserved factors may be related to regional policies towards foreign investors Allowing for nonlinearities reveals, in line with theoretical predictions, that the positive effect of agglomeration economies fades as the density of economic activities reaches some limit value.industrial location, negative binomial models, geoadditive models, european union.

ASSESSING THE JOINT INFLUENCE OF ECOLOGICAL AND SOCIOECONOMIC DETERMINANTS OF INCREASES IN THE BUILT-ENVIRONMENT: A STUDY OF TRENDS IN CENTRAL NORTH CAROLINA

This paper advances an empirical model assessing how, over both time and space, changes in land-use respond to changing economic and ecological conditions. Focusing on Central North Carolina, a region that has undergone extensive changes in forest cover and agricultural lands over the past two decades, landscape dynamics are modeled by exploiting a spatial database that links several satellite images spanning the years 1975-1999 to a suite of socioeconomic, institutional and GIS-created explanatory variables.Environmental Economics and Policy, Land Economics/Use,

Random coefficient autoregressive processes describe Brownian yet non-Gaussian diffusion in heterogeneous systems

Many studies on biological and soft matter systems report the joint presence of a linear mean-squared displacement and a non-Gaussian probability density exhibiting, for instance, exponential or stretched-Gaussian tails. This phenomenon is ascribed to the heterogeneity of the medium and is captured by random parameter models such as "superstatistics" or "diffusing diffusivity". Independently, scientists working in the area of time series analysis and statistics have studied a class of discrete-time processes with similar properties, namely, random coefficient autoregressive models. In this work we try to reconcile these two approaches and thus provide a bridge between physical stochastic processes and autoregressive models. We start from the basic Langevin equation of motion with time-varying damping or diffusion coefficients and establish the link to random coefficient autoregressive processes. By exploring that link we gain access to efficient statistical methods which can help to identify data exhibiting Brownian yet non-Gaussian diffusion.Comment: 28 pages, 9 figures, IOP LaTe

Planar growth generates scale free networks

In this paper we introduce a model of spatial network growth in which nodes are placed at randomly selected locations on a unit square in $\mathbb{R}^2$, forming new connections to old nodes subject to the constraint that edges do not cross. The resulting network has a power law degree distribution, high clustering and the small world property. We argue that these characteristics are a consequence of the two defining features of the network formation procedure; growth and planarity conservation. We demonstrate that the model can be understood as a variant of random Apollonian growth and further propose a one parameter family of models with the Random Apollonian Network and the Deterministic Apollonian Network as extreme cases and our model as a midpoint between them. We then relax the planarity constraint by allowing edge crossings with some probability and find a smooth crossover from power law to exponential degree distributions when this probability is increased.Comment: 27 pages, 9 figure

A Fresh Scrutiny on Openness and Per Capita Income Spillovers in Chinese Cities: A Spatial Econometric Perspective

This paper investigates openness and per capita income spillovers over 367 Chinese cities in the year 2004. Per capita income is modelled as dependent on investment, physical and social infrastructure, human capital, governmental policies and openness to the world. Our empirical analysis improves substantially the previous research in several respects: Firstly, by extending the data set to prefecture-level, it tackles the aggregation bias. Secondly, the introduction of recently developed explanatory spatial data analysis (ESDA) and spatial regression techniques allows to address misspecification issues due to spatial dependence. Thirdly, the endogeneity problem in the regression is taken into consideration through the use of generalised method of moments (GMM) estimator. Our major findings are in Chinese cities, physical and social infrastructure development, human capital and investment could be recognised as major driving sources of per capita income (i), whereas, the government expenditure ratio exerts a negative impact on per capita GDP level (ii). Our empirical findings also yield evidence on the existence of FDI and foreign trade spillovers in China (iii). These findings are robust to a number of alternative spatial weighting matrix specifications.

The Euro and European Financial Market Integration

We use a time-varying copula model to investigate the impact of the introduction of the Euro on the dependence between seventeen European stock markets during the period 1994-2003. The model is implemented with a GJR-GARCH-t model for the marginal distributions and the Gaussian copula for the joint distribution, which allows capturing time-varying, non-linear relationships. The results show that within the euro area, market dependence increased after the introduction of the common currency only for large equity markets, such as in France, Germany, Italy, the Netherlands and Spain, while transaction costs remain important barriers to investment in and thus integration of smaller markets. Structural break tests indicate that the increase in financial market integration started around the beginning of 1998 when euro membership was determined and the relevant information was announced. We also estimate time-varying dependence measures for non-euro European countries with the euro-zone equity market. The UK and Sweden, but not other countries outside the euro area, are found to exhibit an increase in equity market co-movement, which is consistent with the interpretation that these countries may be expected to join the euro in the future.Euro, financial markets, integration, copula, GARCH, international finance