An experimental test of automatic mitigation of wholesale electricity prices

In several major deregulated electricity generation markets, the market operator uses an “automatic mitigation procedure” (AMP) to attempt to suppress the exercise of market power. A leading type of AMP compares the offer price from each generation unit with a recent historical average of accepted offer prices from that same unit during periods when there was no transmission-system congestion to impede competition. If one or more units' offer prices exceed the recent historical average by more than a specified margin, and if these offer prices raise the market-clearing price by more than a specified margin, the market operator replaces the offending offer prices with lower ones. In an experiment, we test an AMP of this type. We find that it keeps market prices close to marginal cost if generation owners have low market power in uncongested periods. However, with high market power in uncongested periods, a condition that may apply in many parts of the world, the generation owners are able to gradually raise the market price well above short-run marginal cost in spite of the AMP. We also test the effect of the AMP on the frequency with which high-variable-cost units are used, inefficiently, in place of low-variable-cost units.     

Commodity prices, trade, and poverty in Uruguay

The 2006-2008 food price spike raised concerns about the impact of high commodity prices on poverty in developing countries. This paper addresses these concerns in relation to Uruguay, a small country that exports agricultural commodities and imports fuels. Applying a general equilibrium model, we find that, as a whole, an increase in commodity prices has a positive effect on the economy of Uruguay. Benefits obtained through a growth in export activities are partially outweighed by an increase in crude oil prices. In this context, extreme poverty increases. As in other countries, the increase in food prices affects the already poor population, who become even poorer. This fact highlights the need for policies that mitigate the negative effects of price shocks.     

Price transmission across the U.S. food distribution system

Price transmission models are estimated using recursive methods across 100 food commodities. From the individual commodities, short- and long-run price transmission coefficients are estimated for rising and falling prices. These coefficients are classified into five commodity categories and expressed as one vector while coding for causality, market levels, rising/falling prices, short and long run, and time period. Then the impact of each variable is estimated and inferences are drawn about the degree of price transmission. Results show that price linkages are strong but slightly declining over time, with some evidence of asymmetric behavior. Long-run rising prices are passed through more than long-run falling prices, except for fruits and vegetables.     

RETAIL GASOLINE PRICE DYNAMICS AND LOCAL MARKET POWER*

Using monthly data from the 48 contiguous states (except Nevada) for the 1988–2002 period, it is shown that retail gasoline prices respond faster to wholesale price increases than to equivalent wholesale price decreases. Moreover, markets with high average retail‐wholesale margins experience a slower adjustment and a more asymmetric response. Since gasoline is the only variable input, average margins in a state likely reflect the degree of retail market power. This suggests that sticky prices and response asymmetries in the gasoline market are, at least partially, a consequence of retail market power.     

The effects of price deregulation on maize marketing margins in South Africa

There has been continuous controversy over the impact of food market reforms on food security in Africa. In South Africa, the government and media have often questioned the effects of price deregulation of maize meal, the major staple food, on consumers. This article determines the effect of retail price deregulation on the size of maize milling/retail margins in South Africa. Regression models of monthly milling/retail margins are run from the period May 1976 to December 2004. To assess the robustness of our findings, we estimate several different models of structural change, vary the sample period to examine the sensitivity of findings to unusual weather and market conditions in the region during episodes between 2001 and 2004, and run the models using different estimation techniques, OLS with Newey-West robust estimators and Feasible General Least Squares. In virtually all models, the results indicate that real maize milling/retailing margins in South Africa have increased by at least 20% since the deregulation of retail prices in 1991. Moreover, there is evidence of trend growth in the size of the milling margin over time. Simulations indicate that the deregulation of maize meal prices has entailed a transfer of at least US$179 million/year from consumers to agents in the marketing system. Further study is needed to understand why this outcome in South Africa differs from findings in other countries in the region concerning the effects of reform on food marketing margins.     

Rice market integration and food security in Nepal: The role of cross-border trade with India

Coarse rice market integration between Nepal and India is analyzed applying a threshold autoregressive model. The price response behaviour of traders is found to be consistent with an asymmetric price adjustment mechanism, indicating coarse rice prices in Nepal respond to shocks originating in India. The results show that adjustments to negative price deviations from long-run stable equilibrium are faster than adjustments to the positive ones given a null threshold. Given that trade flows mainly from India to Nepal, Nepali traders would adjust their prices upward to align with the long-run equilibrium value relatively more quickly in the case of negative price deviations, than if the price deviations were positive. Such a high speed of adjustment to negative price deviations could be detrimental to net food buyers’ food security status in the absence of a price stabilization mechanism. However, a price stabilization policy in Nepal, a food deficit and import dependent country, would hardly have any effect on prices unless further effort is made to build up the level of national food reserves for short-term food security interventions. In the current context of structurally low levels of national food reserves, an alternative short-term policy such as foreign aid, in the form of food or income transfers, targeting the most vulnerable households to price increases is necessary through social safety net programmes. In the long-run, an improvement of transportation infrastructure between market hubs (other than the Biratnagar trade basin) in the Terai (Nepal) and India would contribute to the reduction of transaction costs and create incentives for more competition in formal cross-border trade with India. In times of negative shocks such as the high food price crisis in 2008, restrictive food trade policies in India will continue to undermine household food security in Nepal.     

Speculative storage in imperfectly competitive markets

Markets for many commodities are characterized by imperfectly competitive production as well as substantial storage by speculators who are attracted by significant price volatility. We examine how speculative storage affects the behavior of an oligopoly producing a commodity for which demand is subject to random shocks. Speculators compete with consumers when purchasing the commodity and then subsequently compete with producers when selling their stocks, resulting in two opposing incentives: on the one hand, producers would like to increase production to capture future sales in advance by selling to speculators; while on the other hand, they would like to withhold production to deter speculation, thereby eliminating the additional supply from speculators in future periods. We find that the incentive to sell to speculators can be quite strong, potentially resulting in prices sufficiently high to drive consumers from the market. Furthermore, these incentives are non-monotonic in the number of producers: speculative storage occurs more frequently in a relatively concentrated oligopoly than in the extremes of monopoly or perfect competition.     

The impact of maize price shocks on household food security: Panel evidence from Tanzania

Using three waves (2008/09, 2010/11, 2012/13) of the Tanzanian National Panel Survey, this study investigates the impact of maize price shocks on household food security. Between 2008/09 and 2012/13, calorie intake stagnated for urban households, yet sharply deteriorated for rural households. The latter was driven by a significant decline in the consumption of the major staple maize which showed strongest price hikes among all major food items. Fixed-effects regressions indicate a clear negative relationship between maize prices and average household energy intake. Almost all population groups were found to be negatively affected by maize price shocks, with rural landless households being the most vulnerable group. In particular, a 50 percent rise in maize prices decreases caloric intake for rural (urban) households on average by 4.4 (5.4) percent, and for rural landless households by 12.6 percent. Results further indicate that subsistence agriculture can act as an effective strategy to insure against food price volatility.     

Ordered search in differentiated markets

This paper presents an ordered search model in which consumers search both for price and product fitness. I construct an equilibrium in which there is price dispersion and prices rise in the order of search. The top firms in consumer search process, though charge lower prices, earn higher profits due to their larger market shares. Compared to random search, ordered search can induce all firms to charge higher prices and harm market efficiency.     

Demand,Information, and Competition: Why Do Food Prices Fall at Seasonal Demand Peaks?

Prices for seasonal food products fall at demand peaks. Price declines are not driven by falling agricultural input prices; indeed, farm to retail margins narrow sharply. I use electronic scanner data from a sample of US supermarkets to show that seasonal price declines are closely linked to market concentration, and are much larger in markets with several rivals than where a single brand dominates. Seasonal demand increases reduce the effective costs of informative advertising, and increased informative advertising by retailers and manufacturers in turn may allow for increased market information and greater price sensitivity on the part of buyers.     

Long-term crop productivity response and its interaction with cereal markets and energy prices

Crop yields are endogenous as long as economic agents adjust to permanent changes in expected prices. The literature, however, does not offer a definitive value of how much yield would change in response to sustained price changes. To fill the gap, we use available scientific findings and data to estimate yield elasticities that enable agricultural commodity and food policy analysis. Using a world market model with short- to long-run yield response, we show the impacts of sustained energy price shocks on global cereal supply and demand. The results highlight substantial differences in quantity and price effects depending on the yield elasticities. These results demonstrate the need to recognize yield response when assessing impacts of energy prices or biofuel production on food uses or, more generally, on food security in the face of income and population growth, evolving dietary patterns, climate change implications, or other long-run pressures.     

国际油价冲击与中国的经济增长——基于非对称关系视角的分析

本文基于季度数据，引入非对称协整模型，考察国际油价与中国经济增长的动态关系，并鉴于油价波动对不发达经济体可能的冲击，还测度了油价的不确定性并探析其对经济增长的影响，结果表明：（1）从短期来看，国际油价变化是国内经济增长的单向Granger原因，“中国因素”对全球油价变化的影响尚不明显；（2）从长期来看，国际油价和经济增长具有非对称协整关系，油价上涨对经济的影响明显大于油价下跌所产生的效应；（3）国际石油市场存在正反馈交易行为，导致油价波动在油价上涨时表现更加明显。油价不确定性在短期内对经济增长存在负面影响，长期中则不会显著影响经济增长。以上结果意味着必须高度重视石油安全问题，加强油价波动预警与风险管理系统。     

Real Estate,the External Finance Premium and Business Investment: A Quantitative Dynamic General Equilibrium Analysis

This article studies the connection between the capital market and the real estate market. Empirically, we find that positive real house price shocks lower the external finance premium and stimulate nonresidential investment and real gross domestic product (GDP). Our theoretical framework is able to mimic the volatility of the external finance premium, the relative price of real estate and capital and the investment in real estate and capital. It also captures the cyclicality of the external finance premium and of real estate prices. The contribution of real estate price fluctuations to the variability of the external finance premium and the GDP is confirmed to be significant.     

Local impacts of a global crisis: Food price transmission,consumer welfare and poverty in Ghana

This paper takes a local perspective on global food price shocks by analyzing food price transmission between regional markets in Ghana. It also assesses the impacts of food price increases on various household groups. Taking the 2007–2008 global food crisis as an example, we show that prices for domestic grain products are highly correlated with world market prices. This is true both for products for which Ghana is highly import-dependent (e.g., rice) and the products for which Ghana is self-sufficient (e.g., maize). The econometric results also show that price transmission is high between regional producer markets and markets located in the country’s largest cities, and the distance between producer and consumer markets and the size of consumer markets matter in explaining the price transmission. The welfare analysis for households as consumers shows that the effect of world food prices appears relatively modest for the country as a whole due to relatively diverse consumption patterns within country. However, the national average hides important regional differences, both between regions and within different income groups. We find that the poorest of the poor—particularly those living in the urban areas—are hardest hit by high food prices. The negative effect of the food crisis is particularly strong in northern Ghana. The main explanations for this regional variation in the price effect is the different consumption patterns and much lower per capita income levels in the North of Ghana compared to other regions in the country.     

WHEN DO CONSUMERS SEARCH?*

This paper provides empirical evidence relating search to price movements. We measure consumer search directly from traffic statistics for web sites that report gasoline prices. We show empirically that consumers search more as prices rise than they do when prices fall. Asymmetric search patterns have consequences for price behavior. Our findings indicate that retail margins are squeezed by increased search. In addition, we show that there is more price dispersion when prices are falling than when prices are either stable or rising. Our results provide a search‐based explanation for the ‘rockets and feathers’ phenomenon of asymmetric price adjustment.     

Buyer confusion and market prices

We employ a price setting duopoly experiment to examine whether buyer confusion increases market prices. Each seller offers a good to buyers who have homogeneous preferences. Sellers decide on the number of attributes of their good and set prices. The number of attributes bears no cost to the sellers and does not affect the value of the good to the buyers but adds complexity to buyers’ evaluation of the goods. The experimental results indicate that the buyers make more suboptimal choices and that prices are higher when the number of attributes of the goods is higher. Moreover, prices and profits are higher than those in a benchmark treatment with perfectly rational (robot) buyers.     

Food,energy and environment: Is bioenergy the missing link?

We study price linkages between the food, energy and bioenergy markets. A vertically integrated multi-input, multi-output market model allows us to derive testable hypothesis, which we test by applying time-series analytical mechanisms to nine major traded food commodity prices along with one weighted average world crude oil price. The data consists of 939 weekly observations from January 1993 to December 2010. The empirical findings confirm the theoretical hypothesis that the prices for crude oil and food commodities are interdependent: a USD 1/barrel increase in oil prices and food commodity prices increase by between USD 0.09/tonne and USD 1.65/tonne.     

Does inflation kill? Exposure to food inflation and child mortality

Unlike extreme malnutrition shocks, such as famine and drought which grab the attention of the media, international aid organizations and policymakers, malnutrition due to food price hikes are often neglected and their impacts on children are not well known. It is well established that malnutrition during the critical periods of early life – between conception and the first 1000 days after birth – has lasting consequences on health and mortality. In this paper, using a uniquely constructed data from Ethiopia that takes advantage of high-frequency local retail food prices, we examine the impact of early life exposure to food price inflation on child mortality. Following survival events since conception, we estimate the causal impact of exposure to inflation during in-utero and infancy. The results show that exposure to a 10 percent inflation in staple food prices during in-utero decreases the survival of children under the age of five by about 5.4 percent. We also find that the impacts are non-linear depending on the specific month of exposure and substantially vary by observable characteristics and the type of staple food.     

Group identity in markets

We present a laboratory experiment that measures the effects of group identity—one's perceived membership in social groups—on market transactions in an oligopoly market with a few sellers and buyers. We artificially induce group identity using art preferences and college majors in different treatments, respectively. Subjects are randomly assigned into the roles of buyers and sellers and interact repeatedly. We find that the presence of groups influences both the selection of trading partners and the determination of prices. All else equal, sellers are more likely to make offers to ingroup buyers, and the buyers are more likely to accept offers from ingroup sellers. There are considerable intergroup price differentials with the outgroup sellers charging a lower price than the ingroup sellers.     

Effects of Macroeconomic Uncertainty and Labor Demand Shocks on the Housing Market

This article shows that macroeconomic uncertainty affects the housing market in two significant ways. First, uncertainty shocks adversely affect housing prices but not the quantities that are traded. Controlling for a broad set of variables in fixed‐effects regressions, we find that uncertainty shocks reduce both housing prices and median sales prices in the amount of 1.4% and 1.8%, respectively, but the effect is not statistically significant for the percentage changes of all homes sold. Second, when both uncertainty and local demand shocks are introduced, the effects of uncertainty on the housing market dominate that of local labor demand shocks on housing prices, median sale prices, the share of houses selling for a loss and transactions. The aforementioned effects are largest for the states that exhibit relatively high housing price volatilities, suggesting real options effects in the housing market during the times of high uncertainty.