Bubbles and rationality in bitcoin

Periodically collapsing rational bubbles model speculative demand in asset markets. The price and quantity of bitcoin are integrated of different orders, which is evidence of a bubble. Cointegration tests that allow for the potential presence of such bubbles with alternative proxies for fundamentals cannot reject a bubble in bitcoin.     

Asymmetric information in a competitive market game: Reexamining the implications of rational expectations

Summary. We examine price formation in a simple static model with asymmetric information, an infinite number of risk neutral traders and no noise traders. Here we re-examine four results associated with rational expectations models relating to the existence of fully revealing equilibrium prices, the advantage of becoming informed, the costly acquisition of information, and the impossibility of having equilibrium prices with higher volatility than the underlying fundamentals. Received: August 27, 1997; revised version: February 11, 1998     

预算软约束与资产价格理性泡沫

文章将预算软约束引入资产价格理性泡沫的分析之中,在给出一个预算软约束情形下资产均衡价格决定模型的基础上,得出了资产价格理性泡沫的表达式.模型分析表明,当存在预算软约束时风险资产的理性泡沫为正;同时,风险资产对应企业面临的预算软约束越大,该风险资产价格中的理性泡沫越大.     

Rational panics and stock market crashes

This paper offers an explanation for stock market crashes which focuses on the role of rational but uninformed traders. We show that uninformed traders can precipitate a price crash because as prices decline, they surmise that informed traders received negative information, which leads them to reduce their demand for assets and drive the price of stocks even lower. The model yields several implications, such as that crashes can occur even when the fundamentals are strong, and that the magnitude of the crash depends on the fraction of uninformed investors and the amount of unsophisticated passive investing present in the market.     

Detecting Imbalances in House Prices: What Goes Up Must Come Down?*

I suggest a toolkit of four bubble‐detection methods that can be used to monitor developments in house prices. These methods are applied to US, Finnish, and Norwegian data. For the United States, all measures unanimously suggest a bubble in the early to mid‐2000s, whereas current US house prices are found to be aligned with economic fundamentals. One of the measures indicates imbalances in Finland, while there are no signs of a bubble in Norway. I find that large parts of the US house price bubble can be explained by the sharp increase in capital inflows and the extension of loans to the subprime mortgage market.     

Loss aversion and market crashes

This study proposes a rational expectation equilibrium model of stock market crashes with information asymmetry and loss averse speculators. We obtain a state-dependent linear optimal trading strategy, which makes the equilibrium price tractable. The model predicts nonlinear market depth and the result that small shocks to fundamentals (e.g., supply or informational shocks) can cause abrupt price movements. We demonstrate that short-sale constraints intensify asset price collapses relative to upward movements. The model also generates contagion between uncorrelated assets. These results are consistent with the main puzzling features observed during market crashes, namely abrupt and asymmetric price movements that are not driven by major news events but coupled with a spillover effect between unrelated markets.     

The risk of falling house prices in Italy

This paper shows that Italian house market is less exposed to price shocks than the American one. Variations in the house price index in real terms have been studied along with the affordability ratio and the relation between house prices and rent levels for the period 1995–2004 in Italian provinces. Comparison with US data reveals greater overpricing in the US during the expansion phase (2000–2004). Although a speculative bubble in all US metropolitan areas considered does not emerge, US financial and economic structural factors make the US real estate sector more exposed to price shocks. To test the compatibility of Italian house prices with fundamentals an econometric model is designed to analyze the provincial house prices from 1995 to 2003.     

Irrational exuberance in the Chinese iron ore market?

The rapid run-ups in the Chinese iron ore market in the first half of 2016 have sparked much concern about the appearance of speculative bubbles in this market among many market analysts. Using a recently developed bubble testing procedure, we confirm that there indeed existed periods of irrational exuberance in the Chinese iron ore market. However, most of the bubble periods are short-lived, reflecting the market’s ability to quickly respond to price deviations unjustified by fundamentals. The longest bubble period occurred in mid-2014, corresponding to a period of relatively low trading volume. Using a fractional probit model, we find evidence consistent with the hypothesis that market liquidity may play a role in bubble occurrences.     

Information Markets and the Comovement of Asset Prices

Traditional asset pricing models predict that covariance between prices of different assets should be lower than what we observe in the data. This paper introduces markets for information that generate high price covariance within a rational expectations framework. When information is costly, rational investors only buy information about a subset of the assets. Because information production has high fixed costs, competitive producers charge more for low-demand information than for high-demand information. The low price of high-demand information makes investors want to purchase the same information that others are purchasing. When investors price assets using a common subset of information, news about one asset affects the other assets' prices; asset prices comove. The cross-sectional and time-series properties of comovement are consistent with this explanation.     

HOUSING PRICE AND FUNDAMENTALS IN A TRANSITION ECONOMY: THE CASE OF THE BEIJING MARKET

This article develops a dynamic rational expectations general equilibrium framework that links house value to fundamental economic variables such as income growth, demographics, migration, and land supply. Our framework handles nonstationary dynamics as well as structural changes in fundamentals that are commonplace in transition economies. Applying the framework to Beijing, we find that the equilibrium house price and rent under reasonable parameterizations of the model are substantially lower than the data. We explore potential explanations for the discrepancies between the model and the data.     

Manipulating market sentiment

We analyze a simple model of an asset market, in which a large rational trader interacts with “noise speculators” who seek short-run speculative gains, and become active following a prolonged episode of mispricing relative to the asset’s fundamental value. The model gives rise to price patterns such as bubble dynamics, positive short-run correlation and vanishing long-run correlation of price deviations from the fundamental value. We argue that this example model sheds light on the question as to whether rational speculators abet or curb price fluctuations.     

Arbitrage costs and nonlinear adjustment in the G7 stock markets

This article aims to study stock price adjustments towards fundamentals due to the existence of arbitrage costs defined as the sum of transaction costs and a risky arbitrage premium associated with the uncertainty characterizing the fundamentals. Accordingly, it is shown that a two regime Smooth Transition Error Correction Model (STECM) is appropriate to reproduce the dynamics of stock price deviations from fundamentals in the G7 countries during the period 1969 to 2005. This model takes into account the interdependences or contagion effects between stock markets. Deviations appear to follow a quasi random walk in the central regime when prices are near fundamentals (i.e. when arbitrage costs are greater than expected arbitrage profits, the mean reversion mechanism is inactive), while they approach a white noise in the outer regimes (i.e. when arbitrage costs are lower than expected arbitrage profits, the mean reversion is active). Interestingly, as expected when arbitrage costs are heterogeneous, the estimated STECM shows that stock price adjustments are smooth and that the convergence speed depends on the size of the deviation. Finally, using two appropriate indicators proposed by Peel and Taylor (2000), both the magnitudes of under and overvaluation of stock price and the adjustment speed are calculated per date in the G7 countries. These indicators show that the dynamics of stock price adjustment are strongly dependent on both the date and the country under consideration.     

RECURRENT BUBBLES*

We study rational bubbles in a standard linear asset price model. We first consider a class of bubble processes driven by multiplicative i.i.d. shocks. We show that a bubble process in this class either diverges to infinity with probability one, converges to zero with probability one, or keeps fluctuating forever with probability one, depending on investors' “confidence” in expected bubble growth. We call a bubble process having the last property “recurrent.” We develop sufficient conditions for a bubble process to be recurrent when it is driven by non‐i.i.d. shocks, when the risk‐free interest rate is not constant, and when the process is driven by non‐i.i.d. shocks and the risk‐free interest rate is not constant. In the last case we demonstrate via simulation that there can be a prolonged period in which both the bubble and the interest rate stay close to zero.     

Asset price volatility in a nonconvex general equilibrium model

Summary. Asset prices and returns are known to vary significantly more than␣output or aggregate consumption growth, and an order of magnitude in excess of what is justified by innovations to fundamentals. We study excess price volatility in a lifecycle economy with two assets (claims on capital and␣a public debt bubble), heterogeneous agents, and increasing returns to financial intermediation. We show that a relatively modest nonconvexity generates a set valued equilibrium correspondence in asset prices, with two␣stable branches. Price volatility is the outcome of an equilibrium selection mechanism, which mixes adaptive learning with “noise”, and alternates stochastically between the two stable branches of the price correspondence. Received: March 19, 1998; revised version: June 2, 1998     

Fairness, price stickiness, and history dependence in decentralized trade

The paper investigates price formation in a decentralized market with random matching. Agents are assumed to have subdued social preferences: buyers, for example, prefer a lower price to a higher one but experience reduced utility increases below a reference price that serves as a common fairness benchmark. The strategic equilibrium reflects market fundamentals, but it is markedly less sensitive to the buyer–seller ratio near the fair price benchmark. Prices may be sticky around very different reference levels in markets with otherwise identical fundamentals. The implied history dependence turns out to be mitigated rather than exacerbated by friction.     

The influence of investment experience on market prices: laboratory evidence

We run laboratory experiments to analyze the impact of prior investment experience on price efficiency in asset markets. Before subjects enter the asset market they gain either no, positive, or negative investment experience in an investment game. To get a comprehensive picture about the role of experience we implement two asset market designs. One is prone to inefficient pricing, exhibiting bubble and crash patterns, while the other exhibits efficient pricing. We find that (i) both, positive and negative, experience gained in the investment game lead to efficient pricing in both market settings. Further, we show that (ii) the experience effect dominates potential effects triggered by positive and negative sentiment generated by the investment game. We conjecture that experiencing changing price paths in the investment game can create a higher sensibility on changing fundamentals (through higher salience) among subjects in the subsequently run asset market.     

Learning rational expectations in an asset market

Will traders in a risky asset market learn Muthian expectations when they initially lack the necessary information? If some traders learn from their observations, will market dynamics depend only on “fundamentals,” as implied by the Efficient Market Hypothesis? This paper shows that at any finite point in time the answer to these questions is “no”. The context is a constant absolute risk aversion model with two kinds of traders and asymmetric information. The market converges asymptotically to a rational expectations equilibrium where prices depend only on fundamentals and the market is efficient.     

OPTIMAL MONETARY POLICY AND ASSET PRICE MISALIGNMENTS

This paper analyses the relationship between monetary policy and asset prices in the context of optimal policy rules. The transmission mechanism is represented by a linearized rational expectations model augmented for the effect of asset prices on aggregate demand. Stabilization objectives are represented by a discounted quadratic loss function penalizing inflation and output gap volatility. Asset prices are allowed to deviate from their intrinsic value due to momentum trading. We find that in the presence of wealth effects and inefficient markets, asset price misalignments from their fundamentals should be included in the optimal interest rate reaction function.     

China’s house price: Affected by economic fundamentals or real estate policy?

Many theory and empirical literature conclude that house price can reflect economic fundamentals in the long-term. However, by using China’s panel data of 35 main cities stretching from 1998 to 2007, we find that there is no stable relationship between house price and economic fundamentals. House price has deviated upward from the economic fundamentals since government started macro-control of the real estate market. We consider that the mechanism between the house price and economic fundamentals is distorted by China’s real estate policy, especially its land policy. Meanwhile the policy itself is an important factor in explaining the changes of China’s house price. Then we estimate the dynamic panel data model on house price and the variables which are controlled by real estate policy. The result shows: land supply has negative effects on house price; financial mortgages for real estate have positive effects on house price; and the area of housing sold and the area of vacant housing, which reflects the supply and demand of the housing market, has negative effects on house price. We also find some differences in house price influence factor between eastern and mid-western cities. Finally, we propose policy suggestions according to the empirical results.