the presence of bubbles in the markets and its formation has been regarded by economists and they have been looking to develop methods that can be recognized by using appropriate method for the formation of bubbles. in this paper, first, the formation of bubbles is tested using the new unit root test known as phillips test (generalized sup adf test) for 50 companies in the tehran stock exchange...

The sharp increase in agricultural commodity prices in 2008 and in 2011 has triggered an intensive debate on the causes for these price booms. Speculative bubbles have been quoted as one factor among others for the price peaks. Against this background, our paper contributes to this discussion by implementing a novel test procedure for speculative bubbles which has been suggested in the stock ma...

Abstract We develop a model of rational bubbles based on leverage and the assumption an imprecisely known maximum market size. In bubble, traders push asset price above its fundamental value in dynamic way, driven by expectations about future developments. At previously unknown date, bubble will endogenously burst. Households optimally decide whether to lend with limited liability. Bubbles incr...

This paper introduces a noncausal autoregressive process with Cauchy errors in application to the exchange rates of the Bitcoin electronic currency against the US Dollar. The dynamics of the daily Bitcoin/USD exchange rate series displays episodes of local trends, which can be modelled and interpreted as speculative bubbles. The bubbles may result from the speculative component in the on-line t...

This paper introduces a noncausal autoregressive process with Cauchy errors in application to the exchange rates of the Bitcoin electronic currency against the US Dollar. The dynamics of the daily Bitcoin/USD exchange rate series displays episodes of local trends, which can be modelled and interpreted as speculative bubbles. The bubbles may result from the speculative component in the on-line t...