The Effects of Subject Pool and Design Experience on Rationality in Experimental Asset Markets

Empirical evidence suggests that prices do not always reflect fundamental values and individual behavior is often inconsistent with rational expectations theory. We report the results of fourteen experimental asset markets designed to examine whether the interactive effect of subject pool and design experience (i.e., previous experience in a market under identical conditions) tempers price bubbles and improves forecasting ability. Our main findings are: 1) price run-ups are modest and dissipate quickly when traders are knowledgeable about financial markets and have participated in a previous market under identical conditions; 2) price bubbles moderate quickly when only a subset of traders are knowledgeable and experienced; 3) the heterogeneity of expectations about price changes is smaller in markets with knowledgeable and experienced traders, even if such traders only represent a subset of the market; and 4) individual forecasts of prices are not consistent with the predictions of the rational expectations model in any market, although absolute forecast errors are smaller for subjects who are knowledgeable of financial markets and for those subjects who have participated in a previous market. In sum, our findings suggest that markets populated by at least a subset of knowledgeable and experienced traders behave rationally, even though average individual behavior can be characterized as irrational.     

Rock around the clock: An agent-based model of low- and high-frequency trading

We build an agent-based model to study how the interplay between low- and high-frequency trading affects asset price dynamics. Our main goal is to investigate whether high-frequency trading exacerbates market volatility and generates flash crashes. In the model, low-frequency agents adopt trading rules based on chronological time and can switch between fundamentalist and chartist strategies. By contrast, high-frequency traders activation is event-driven and depends on price fluctuations. High-frequency traders use directional strategies to exploit market information produced by low-frequency traders. Monte-Carlo simulations reveal that the model replicates the main stylized facts of financial markets. Furthermore, we find that the presence of high-frequency traders increases market volatility and plays a fundamental role in the generation of flash crashes. The emergence of flash crashes is explained by two salient characteristics of high-frequency traders, i.e., their ability to i. generate high bid-ask spreads and ii. synchronize on the sell side of the limit order book. Finally, we find that higher rates of order cancellation by high-frequency traders increase the incidence of flash crashes but reduce their duration.     

The “inflow-effect”—Trader inflow and price efficiency

We investigate the impact of cash and trader inflow on price efficiency in multi-period experimental asset markets. Implementing eight treatments with 672 subjects, we find that (i) the joint inflow of cash and traders triggers strong overvaluation and massive price run-ups (inflow-effect). Remarkably, the effect occurs in almost all of the 30 markets with joint cash and trader inflow and is very robust. The effect even prevails in markets with complete and symmetric fundamental information. We further show that (ii) in treatments with the joint inflow of cash and traders, prices crash to fundamentals towards maturity of the asset. The analysis of traders׳ beliefs reveals that (iii) despite fundamental values staying constant, beliefs about fundamentals co-move with upwardly trending prices. Finally, we report a speculative motive only among the optimists in treatments where we observe the inflow-effect.     

“Overreaction” of Asset Prices in General Equilibrium

We attempt to explain the overreaction of asset prices to movements in short-term interest rates, dividends, and asset supplies. The key element of our explanation is a margin constraint that traders face which limits their leverage to a fraction of the value of their assets. Traders may lever themselves, furthermore, either directly by borrowing short term or indirectly by engaging in futures and options trading, so that the scenario is relevant to contemporary financial markets. When some shock pushes asset prices to a low enough level at which the margin constraint binds, traders are forced to liquidate assets. This drives asset prices below what they would be with frictionless markets. Also, a shock which simply increases the likelihood that the margin constraint will bind can have a very similar effect on asset prices. We construct a general equilibrium model with margin constrained traders and derive some qualitative properties of asset prices. We present an analytical solution for a deterministic version of the model and a simple numerical computation of the stochastic version.Journal of Economic LiteratureClassification Numbers: G1, E0.     

Price Limits, Information Acquisition, and Bid–ask Spreads: Theory and Evidence

A number of futures markets use price limits which, in effect, preclude trade from occurring at prices outside certain exogenous bounds. Noting that such markets are characterized by heterogeneously informed traders, whereas previous work on price limits assumes symmetrically informed traders, we examine the effects of price limits in a setting where market participants are asymmetrically informed. We find that imposing price limits generally lowers the quality of information acquired in equilibrium, but lowers bid–ask spreads as well. Thus, depending on the relative weights placed by society on liquidity versus price efficiency, there may exist a set of price limits that are most efficient in achieving a trade-off between liquidity and informational efficiency. We perform empirical tests of some implications of the model using cross-sectional data on price limits. We find that price limits are strongly negatively related to both price volatility and trading volume. Though other explanations for our empirical findings cannot be ruled out, these results are not inconsistent with the model's implication that price limits should be tighter for contracts which offer greater profit potential for informed traders.     

On the Tobin Tax

Abstract

This paper clarifies why a transaction tax, such as the Tobin Tax, can stabilize financial markets. In markets that are already fairly deep, relatively small changes in trading volume are unlikely to have any impact (positive or negative) on volatility. Thus, a Tobin Tax can potentially have a stabilizing effect on international currency markets not because it reduces the excessive volume of transactions of speculators, but because it can slow down the speed with which market traders react to changes in prices of currencies. Moreover, it can lower their elasticity of future price expectations with respect to current price changes, which also has a stabilizing effect. Thus, to the extent that a Tobin Tax causes traders in financial markets to delay their decisions, a few ‘grains of sand in the wheels of international finance’ can indeed be stabilizing. Whether or not that is sufficient to prevent speculative attacks on currencies is a different matter.     

Experimental asset markets with endogenous choice of costly asymmetric information

Asymmetric distribution of information, while omnipresent in real markets, is rarely considered in experimental financial markets. We present results from experiments where subjects endogenously choose between five information levels (four of them costly). We find that (i) uninformed traders earn the highest net returns, while average informed traders always perform worst even when information costs are not considered; (ii) over time traders learn to pick the most advantageous information levels (full information or no information); and (iii) market efficiency decreases with higher information costs. These results are mostly in line with the theoretical predictions of Grossman and Stiglitz (Am. Econ. Rev. 70:393–408, 1980) and provide additional insights that studies with only two information levels cannot deliver.     

Convergence of outcomes and evolution of strategic behavior in double auctions

We study the emergence of strategic behavior in double auctions with an equal number of buyers and sellers, under the distinct assumptions that orders are cleared simultaneously or asynchronously. The evolution of strategic behavior is modeled as a learning process driven by a genetic algorithm. We find that, as the size of the market grows, allocative inefficiency tends to zero and performance converges to the competitive outcome, regardless of the order-clearing rule. The main result concerns the evolution of strategic behavior as the size of the market gets larger. Under simultaneous order-clearing, only marginal traders learn to be price takers and make offers equal to their valuations/costs. Under asynchronous order-clearing, all intramarginal traders learn to be price makers and make offers equal to the competitive equilibrium price. The nature of the order-clearing rule affects in a fundamental way what kind of strategic behavior we should expect to emerge.     

Market for Information and Identity Disclosure in an Experimental Open Limit Order Book

This paper analyses the effects of pre‐trade transparency on market quality in an experimental open limit order book preceded by a market for information. The design of the trading game is akin to the system in use in an increasing number of financial markets. We find that the disclosure of traders' identities reduces the incentive to acquire information, liquidity and volatility. We also show that a positive relation exists between the proportion of traders buying information and liquidity. The results are consistent with a standard model of price formation where the number of informed traders is endogenous .     

Price efficiency and trading behavior in limit order markets with competing insiders

We study price efficiency and trading behavior in laboratory limit order markets with asymmetrically informed traders. Markets differ in the number of insiders present and in the subset of traders who receive information about the number of insiders present. We observe that price efficiency (i) is the higher the higher the number of insiders in the market but (ii) is unaffected by changes in the subset of traders who know about the number of insiders present. (iii) Independent of the number of insiders, price efficiency increases gradually over time. (iv) The insiders’ information is reflected in prices via limit (market) orders if the asset’s value is inside (outside) the bid-ask spread. (v) In situations where limit and market orders yield positive profits, insiders clearly prefer market orders, indicating a strong desire for immediate transactions.     

Imperfect competition in agricultural markets: evidence from Ethiopia

Drawing upon unique transaction-level data from rural Ethiopia, this paper tests for general forms of imperfect competition among rural wholesale traders. These are key to the grain distribution system as they purchase from farmers and perform interregional trade. Tests show that traders in a typical source market engage in imperfectly competitive behavior in purchasing from farmers, driving down the price paid to farmers approximately 3%. In contrast, there is no conclusive evidence of imperfect competition among traders in the larger, more centrally located market studied. Thus, efficiency losses due to market structure are likely to be greatest in markets which also have poor road links and lesser volumes of marketed grain.     

异质信念、投机均衡与农产品期货定价*

农产品期货市场套利并不充分,交易者也不是完全理性的。本文假设农产品期货市场有限套利、交易者异质信念并遵循“经验法则”预期,构建了农产品期货投机均衡定价模型,并认为集中竞价规则下产生的农产品期货价格是由交易者的预期决定的;前期期货价格水平、现货价格和前期期货价格的变动趋势、不同类型交易者的比例结构及其预期模式共同影响农产品期货价格的形成与波动;基本分析法交易者占主导地位的农产品期货市场具有更高的套期保值与价格发现效率。针对中国七种主要农产品期货的实证结果显示,农产品期货投机均衡定价模型对解释中国农产品期货价格的形成与波动是有效的。这意味着在期货行情系统中实时披露现货价格信息,培育和引导交易者运用基本分析法预测期货价格走势,有助于提升农产品期货市场的效率。     

Volatility transmission between oil prices and banks' stock prices as a new source of instability: Lessons from the United States experience

This paper examines whether American banks' exposure to the oil industry could lead to instability in both oil and financial markets. To address this issue, we investigate volatility spillovers between oil prices and the stock prices of the four major American banks involved in the oil industry by employing the vector autoregressive fractionally integrated moving average framework. We use high-frequency data from January 3, 2006, to June 30, 2016. Our results support the existence of such volatility spillovers, as evidenced by the significant volatility responses of oil price (banks' stock price) to a shock in banks' stock price (oil price). These responses, more pronounced following the banks' exposure to the shale industry, mainly reflect the financial fragility of shale companies and their high indebtedness levels. Thus, this paper emphasises how the shale oil industry could trigger turmoil in both oil and financial markets.     

Language sentiment in fundamental and noise trading: evidence from crude oil

ABSTRACT

Recent research has found the language sentiment in financial news to be a substantial driver of prices in financial markets, though there are two diametrically opposed interpretations for this: either markets perceive news sentiment as fundamental information (thus leading to changes in the valuation of assets) or news sentiment conveys a noise signal (thus contributing to the stochastic component of prices). The opposite roles are resolved in the context of crude oil prices by decomposing price movements into two components referring to fundamental and noise trading. Contrary to theoretical arguments in prior literature, we find empirical results supporting both interpretations.     

Volatility–volume co-movements: evidence from China metal markets

This article investigates the interactional relationship between price volatility and futures trading activity for three heavily traded metal products on the Shanghai Metal Exchange and the Shanghai Futures Exchange. Using models based on vector autoregression and generalized method of moments, we show, in particular, that futures trading activity has a strong impact on both spot and futures price volatility in copper and aluminium markets. Futures trading activity leads spot market volatility in copper and aluminium markets which suggests that futures markets have a destabilizing effect. In order to disentangle the effect of different traders’ types on asset price movements, we decompose futures trading into speculators’ and hedgers’ trading and investigate their contributions to volatility. As a robustness check, we investigate the impact of endogenous structural breaks on the interactional relationship between price volatility and futures trading.     

Competitive auctions

We study a class of single-round, sealed-bid auctions for an item in unlimited supply, such as a digital good. We introduce the notion of competitive auctions. A competitive auction is truthful (i.e. encourages bidders to bid their true valuations) and on all inputs yields profit that is within a constant factor of the profit of the optimal single sale price. We justify the use of optimal single price profit as a benchmark for evaluating a competitive auctions profit. We exhibit several randomized competitive auctions and show that there is no symmetric deterministic competitive auction. Our results extend to bounded supply markets, for which we also give competitive auctions.     

The equity price channel in a New-Keynesian DSGE model with financial frictions and banking

This paper studies the role of the equity price channel in business cycle fluctuations, and highlights the equity price channel as a different aspect to general equilibrium models with financial frictions and, as a result, emphasizes the systemic influence of financial markets on the real economy. We develop a canonical dynamic general equilibrium model with a tractable role for the equity market in banking, entrepreneur and household economic activities. The model is estimated with Bayesian techniques using U.S. data over the sample period 1982Q01–2015Q01. We show that a dynamic general equilibrium model with an equity price channel well mimics the U.S. business cycle. The model reproduces the strong procyclicality of the equity price. The equity price channel significantly exacerbates business cycle fluctuations through both financial accelerator and bank capital channels. Our results support the increasing emphasis on common equity capital in Basel III regulations. This is beneficial in terms of financial stability, but amplifies and propagates shocks to the real economy.     

Overreactions,Momentum, Liquidity,and Price Bubbles in Laboratory and Field Asset Markets

Laboratory asset markets provide an experimental setting in which to observe investor behavior. Over more than a decade, numerous studies have found that participants in laboratory experiments frequently drive asset prices far above fundamental value, after which the prices crash. This bubble-and-crash behavior is robust to variations in a number of variables, including liquidity (the amount of cash available relative to the value of the assets being traded), short-selling, certainty or uncertainty of dividend payments, brokerage fees, capital gains taxes, buying on margin, and others.

This paper attempts to model the behavior of asset prices in experimental settings by proposing a "momentum model" of asset price changes. The model assumes that investors follow a combination of two factors when setting prices: fundamental value, and the recent price trend. The predictions of the model, while still far from perfect, are superior to those of a rational expectations model, in which traders consider only fundamental value. In particular, the momentum model predicts that higher levels of liquidity lead to larger price bubbles, a result that is confirmed in the experiments. The similarity between laboratory results and data from field (real-world) markets suggests that the momentum model may be applicable there as well.     

Price connectedness between green bond and financial markets

We study price connectedness between the green bond and financial markets using a structural vector autoregressive (VAR) model that captures direct and indirect transmission of financial shocks across markets. Using heteroskedasticity to identify the structural VAR model parameters, our empirical findings reveal that the green bond market is closely linked to the fixed-income and currency markets, receiving sizeable price spillovers from those markets and transmitting negligible reverse effects. We also show that, in contrast, the green bond market is weakly tied to the stock, energy and high-yield corporate bond markets. These findings have implications in terms of portfolio and risk management decisions for environmentally aware investors holding positions in green bonds.     

Random competitive exchange: Price distributions and gains from trade

This paper studies the behavior of a competitive exchange under uncertain preferences and random indivisible endowments. We obtain explicit closed-form results for the price distribution and expected gains from trade, both for case where the market is “thin” and the number of traders is low, and for the asymptotic case where the number of traders tends to infinity. We demonstrate that increasing the number of traders reduces price variability and increases the expected gains from trade, and that increasing the variability of traders' reservation prices increases price variability as well as the expected asymptotic gains from trade.