We propose an extension of the class of rational expectations bubbles (REBs) to the more general rational beliefs … speculation. Accounting for the fact that market efficiency has an intrinsic time dimension, we show that diverse but correlated … beliefs can thus account for speculative bubbles, without the need for irrational agents or limits to arbitrage. Many of the …

properties for detecting bubbles. Empirical analysis using price-dividend ratios of S&P500 highlights the advantages of our …

Asset market bubbles and crashes are a major source of economic instability and inefficiency. Sometimes ascribed to … efficiency, while incidental emotions can impair it. Signals in specific brain areas can be a trigger precipitating a bubble …

A firm's marketing efficiency, the ability to optimally deploy and integrate different marketing inputs to achieve high … sales revenue at low cost, is persistent. High marketing efficiency predicts better future operating performance and stock … returns, especially in competitive industries. A marketing efficiency-based long-short portfolio strategy earns an average …

impact on information efficiency. We construct two meme stock indices based on stocks whose purchase the Robinhood app … restricted during the GameStop episode. We provide evidence of meme stock market efficiency. Our results indicate, perhaps … efficiency …

The promotion of both market fairness and efficiency has long been a goal of securities market regulators worldwide … studies have mostly focused on market efficiency, our study proposes a tool to improve market fairness, even under periods of … transaction is taxed at a higher rate if it does not enhance the efficiency measured by deviation from fundamentals. When an agent …

; market efficiency …