Excess Volatility in European Equity Style Indices - New Evidence
Marian Berneburg
IWH Discussion Papers,
No. 16,
2006
Abstract
Are financial markets efficient? One proposition that seems to contradict this is Shiller’s finding of excess volatility in asset prices and its resulting rejection of the discounted cash flow model. This paper replicates Shiller’s approach for a different data set and extends his analysis by testing for a long-run relationship by means of a cointegration analysis. Contrary to previous studies, monthly data for an integrated European stock market is being used, with special attention to equity style investment strategies. On the basis of this analysis’ results, Shiller’s findings seem questionable. While a long-run relationship between prices and dividends can be observed for all equity styles, a certain degree, but to a much smaller extent than in Shiller’s approach, of excess volatility cannot be rejected. But it seems that a further relaxation of Shiller’s assumptions would completely eliminate the finding of an overly strong reaction of prices to changes in dividends. Two interesting side results are, that all three investment styles seem to have equal performance when adjusting for risk, which by itself is an indication for efficiency and that market participants seem to use current dividend payments from one company as an indication for future dividend payments by other firms. Overall the results of this paper lead to the conclusion that efficiency cannot be rejected for an integrated European equity market.
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Network Investment and the Threat of Regulation – Preventing Monopoly Exploitation or Infrastructure Construction?
Ulrich Blum, Christian Growitsch, Niels Krap
IWH Discussion Papers,
No. 7,
2006
Abstract
In summer 2005, the German telecommunication incumbent Deutsche Telekom announced its plans to build a new broadband fibre optics network. Deutsche Telekom decided as precondition for this new network not to be regulated with respect to pricing and third party access. To develop a regulator's strategy that allows investments and prevents monopolistic prices at the same time, we model an incumbent's decision problem under a threat of regulation in a game-theoretical context. The decision whether to invest or not depends on the probability of regulation and its assumed impact on investment returns. Depending on the incumbent's expectation on these parameters, he will decide if the investment is favourable, and which price to best set. This price is below a non-regulated profit maximising price, since the incumbent tries to circumvent regulation. Thus, we show that the mere threat of a regulator's intervention might prevent supernormal profits without actual price regulation. The regulator, on the other hand, can influence both investment decision and the incumbent's price via his signals on regulation probability and price. These signals an be considered optimal, if they simultaneously allow investment and minimize the incumbent's price.
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