Volatility-price relationships in power exchanges: A demand-supply analysis

The evidence of volatility-price dependence observed in previous works (Karakatsani and Bunn 2004; Bottazzi, Sapio and Secchi 2005; Simonsen 2005) suggests that there is more to volatility than simply spikes. Volatility is found to be positively correlated with the lagged price level in settings where market power is likely to be particularly strong (UK on-peak sessions, the CalPX). Negative correlation is instead observed in markets considered to be fairly competitive, such as the NordPool. Prompted by these observations, this paper aims to understand whether volatility-price patterns can be mapped into different degrees of market competition, as the evidence seems to suggest. Price fluctuations are modelled as outcomes of dynamics in both sides of the market - demand and supply, which in turn respond to shocks to the underlying preference and technology fundamentals. Negative volatility-price dependence arises if the market dynamics is accounted for by common shocks which affect valuations uniformly. Positive dependence is related to the impact of asymmetric shocks. The paper shows that under certain conditions, these volatility-price patterns can be used to identify the exercise of market power. Identification is however ruled out if all shocks affect valuations uniformly.Electricity, Market, Volatility, Supply Curve, Demand Curve, Fundamentals, Shocks

Regaining the Fundamentals

Transport policy and planning has relatively few but important fundamentals. Research has focused on marginal issues and not fundamentals. The paper reviews physical fundamentals, moves through economic and financial, then institutional arrangements, policy-making fundamentals, and finally takes a look into the future. Along the way conclusions are drawn that physical constraints narrow choice greatly; that the problem with growth as an objective is mainly in it’s definition as GDP; that pricing is under-utilised; and that the use of transport as a tax base will become unacceptable. A review of decision-making fundamentals points to a need to change institutional arrangements to better reflect the trade-off between technological scale, creditworthiness and responsiveness to demand, and to counter balance the current power of supply institutions. Finally a new organisational model is proposed that meets the criteria of the framework of the fundamentals discussed in the paper. The model is called a Community Infrastructure Corporation, and works by placing control of supply primarily in the hands of those demanding service

The impact of forward trading on the spot power price volatility with Cournot competition

In this paper, we analyze the influence of forward trading on the volatility of spot power prices, in models where forward contracts are strategic tools used by energy producers to obtain profit security. We define volatility as the variance of the percentage change in spot power prices over a given time interval. As shown in Sapio (2008), volatility is related to stochastic fluctuations in preference and technology fundamentals, and is tuned by the price-elasticity of demand and supply, evaluated at equilibrium. We study two cases. First, we analyze the volatility implications of a model wherein the amount of forward trading is fixed, and producers compete a la Cournot. Fixed forward trading increases spot volatility, because forwards lower the spot price level, corresponding to a less elastic region of a linear demand function. However, if the amount of forward trading is endogenous, as in the two-stage model of Allaz (1992), producers can anticipate the spot market impact of stochastic shocks on fundamentals and 'sterilize' them. As a result, spot price volatility is closer to the value implied by an efficient market. Our theoretical results are illustrated by means of a simple simulation study.Electricity market; Cournot model; forward contract; volatility of spot price; elasticity;

Do Asset Prices Reflect Fundamentals? Freshly Squeezed Evidence from the OJ Market

The behavioral finance literature cites the frozen concentrated orange juice (FCOJ) futures market as a prominent example of the failure of prices to reflect fundamentals. This paper reexamines the relation between FCOJ futures returns and fundamentals, focusing primarily on temperature. We show that when theory clearly identifies the fundamental, i.e., at temperatures close to or below freezing, there is a close link between FCOJ prices and that fundamental. Using a simple, theoretically-motivated, nonlinear, state dependent model of the relation between FCOJ returns and temperature, we can explain approximately 50% of the return variation. This is important because while only 4.5% of the days in winter coincide with freezing temperatures, two-thirds of the entire winter return variability occurs on these days. Moreover, when theory suggests no such relation, i.e., at most temperature levels, we show empirically that none exists. The fact that there is no relation the majority of the time is good news for the theory and for market efficiency, not bad news. In terms of residual FCOJ return volatility, we also show that other fundamental information about supply, such as USDA production forecasts and news about Brazil production, generate significant return variation that is consistent with theoretical predictions. The fact that, even in the comparatively simple setting of the FCOJ market, it is easy to erroneously conclude that fundamentals have little explanatory power for returns serves as an important warning to researchers who attempt to interpret the evidence in markets where both fundamentals and their relation to prices are more complex.

The Dynamic Interaction of Exchange Rates and Trade Flows

During the fifteen years since 1970, the theory of exchange-rate determination has been completely transformed. In the late 1960s, the standard model of the foreign exchange market had supply and demand as stable functions of exports and imports, with the expection that a floating rate would move gradually with relative price changes. However,the period of floating rates that began in the early 1970s has revealed that exchange rates exhibit the volatility of financial market prices.This experience, coupled with development of theory, led first to the"monetary" approach to exchange rate determination and then to the "asset market" approach. The monetary approach to exchange rate determination had essentially one-way causation from money to exchange rates, sometimes via purchasing power parity. The broader asset market approach assumes two-way causation.The exchange rate, in the asset-market view, is proximately determined by financial-market equilibrium conditions. It, in turn, influences the trade balance and the current account. The latter, in its turn, is the rate of accumulation of national claims on foreigners, and this feeds back into financial market equilibrium. Thus the asset market approach contains a dynamic feedback mechanism in foreign assets and exchange rates. This approach is called here a "fundamentals" model of exchange rate dynamics. Recent work on rational expectations adds a layer of expectations to the model. It is assumed that following an unexpected disturbance the market can anticipate where the fundamentals will move the system, and move the exchange rate in anticipation of that fundamentals path. This paper integrates the traditional elasticities and absorption approaches into the general equilibrium fundamentals model, and then add the expectations layer. The model is used to interpret recent shifts in U.S. fiscal policy and portfolio preferences for the dollar.

The metals price boom of 1987-89 : the role of supply disruptions and stock changes

The markets for base metals have changed remarkably in the last few years. A long period of extremely low prices was followed by a sustained price boom in 1987-89 - which continued into 1990 for copper, nickel, lead, and zinc. The author examines the causes of the price boom in terms of market fundamentals. Because of the importance of supply disturbances and low stocks, the reduced-form price equation specification was extended to incorporate supply-side variables. The resulting estimates exhibit superior fit and greater explanatory power than, for example, those of Gilbert's (1986) model. The estimates of the modeland simulations of the boom period with the model suggest the following: 1) The growth of OECD industrial production was the most important factor in the higher metals prices, 2) US dollar depreciation was the dominant contributor to the metals price increase during the earlier part of the boom, 3) supply disturbances and low stocks had positive impacts on the price increases, and 4) excessive market speculation exacerbated the price increases.Access to Markets,Economic Theory&Research,Mining&Extractive Industry (Non-Energy),Environmental Economics&Policies,Markets and Market Access

Electricity futures prices: time varying sensitivity to fundamentals

This paper provides insight in the time-varying relation between electricity futures prices and fundamentals in the form of prices of contracts for fossil fuels. As supply curves are not constant and different producers have different marginal costs of production, we argue that the relation between electricity futures prices and futures prices of underlying fundamentals such as natural gas, coal and emission rights are not constant and vary over time. We test this view by applying a model that linearly relates electricity futures prices to the marginal costs of production and calculate the log-likelihood of different time-varying and constant specifications of the coefficients. To do so, we formulate the model in state-space form and apply the Kalman Filter to observe the dynamics of the coefficients. We analyse historical prices of futures contracts with different delivery periods (calendar year and seasons, peak and off-peak) from Germany and the U.K. The results indicate that analysts should choose a time-varying specification to relate the futures price of power to prices of underlying fundamentals

Handmade series direct-current motor

Using common materials, it is possible to build a variety of very simple - and yet functioning - electric devices. These devices can be used to verify Electromagnetism fundamentals. Electric currents within magnetic fields originate forces and that is the basic principle of operation of electric motors. This paper describes a universal series motor made with iron bars, insulated copper wire, two small brass plates, insulating tape, six screws and a couple of hoops. The motor is fed with a personal computer 12V DC switched power supply. Rotor speed can achieve several rotations per second