Behavior analysis of virtual-item gambling.

From the gambling logs of an online lottery game we extract the probability distribution of various quantities (e.g., bet value, total pool size, waiting time between successive gambles) as well as related correlation coefficients. We view the net change of income of each player as a random walk. The mean-squared displacement of these net income random walks exhibits a transition between a superdiffusive and a normal diffusive regime. We discuss different random-walk models with truncated power-law step lengths distributions that allow us to reproduce some of the properties extracted from the gambling logs. Analyzing the mean-squared displacement and the first-passage time distribution for these models allows us to identify the key features needed for observing this crossover from superdiffusion to normal diffusion.