Ranking algorithms are the information gatekeepers of the Internet era. We develop a stylized framework to study the effects of ranking algorithms on opinion dynamics. We consider rankings that depend on popularity and on personalization. We find that popularity driven rankings can enhance...

We develop a behavioral macroeconomic model in which agents use simple but biased rules to forecast future output and inflation. This model generates endogenous waves of optimism and pessimism (“Animal Spirits”) that are generated by the correlation of biased beliefs. We contrast the...

We use a unique hand collected data set of 6 258 auctions from the online football manager game Hattrick to study micro-patterns of reserve price formation. We find that chosen reserve prices exhibit both, very sophisticated and “irrational” behavior by the sellers. Reserve prices pick up...

I distinguish two types of macroeconomic models. The first type are top-down models in which some or all agents are capable of understanding the whole picture and use this superior information to determine their optimal plans. The second type are bottom-up models in which all agents experience...