Colin Ellis

Examining The Behaviour Of Individual UK Consumer Prices

This article examines how UK consumer prices behave, using two databases with millions of price observations: the microdata that underpin official Consumer Prices Index data and a database of supermarket prices. Prices do not change continuously but our key finding is the marked heterogeneity in the data. That is not consistent with standard microeconomic foundations that typically form the basis of macroeconomic policy models. Declining hazard functions and the distribution of price changes also argue against representative agent models. Our results suggest further work is needed to find a model of price‐setting that genuinely corresponds to how individual UK consumer prices behave.

What Lies Beneath? A Time‐Varying Favar Model for the UK Transmission Mechanism

This paper uses a time-varying Factor Augmented VAR to investigate the evolving transmission of monetary policy and demand shocks in the UK. Simultaneous estimation of time-varying impulse responses of a large set of macroeconomic variables and disaggregated prices suggest that the response of inflation, money supply and asset prices to monetary policy and demand shocks has changed over the sample period. In particular, during the post-1992 inflation targeting period, monetary policy shocks started having a bigger impact on prices, a smaller impact on activity and began contributing more to overall volatility. In contrast, demand shocks had the largest impact on these variables before the 1990s. We also document changes in the response of disaggregated prices, with the median reaction to contractionary policy shocks becoming more negative and the distribution more dispersed post-1992. JEL Classification: C38, E44, E52

How do Individual UK Producer Prices Behave

This paper examines the behaviour of individual producer prices in the United Kingdom, and uncovers a number of stylised facts about pricing behaviour. First, on average 26% of producer prices change each month, although there is considerable heterogeneity between sectors and price changes occur less frequently when measured by the average for individual products. Second, the probability of price changes is not constant over time: prices are most likely to change one, four and twelve months after they were previously set. Third, the distribution of price changes is wide, although a significant number of changes are relatively small and close to zero. Fourth, prices that change more frequently tend to do so by less. And fifth, price changes are much less persistent at the disaggregated level than aggregate inflation data imply. We find that conventional pricing theories struggle to match these results, particularly the marked heterogeneity.

Do Supermarket Prices Change from Week to Week

This paper examines the behaviour of supermarket prices in the United Kingdom, using weekly scanner data supplied by Nielsen. A number of stylised facts about pricing behaviour are uncovered. First, prices change very frequently in supermarkets, with 40% of prices changing each week, and even controlling for ‘temporary’ changes, a quarter of prices change each week. Importantly, there is evidence that focusing on monthly observations, rather than weekly ones, overstates the implied stickiness of prices. Second, the probability of price changes is not constant over time – all product categories have declining hazard functions. Third, the range of price changes is very wide, with some very large price cuts and price rises; but despite this, a significant number of price changes are very small. Fourth, there appears to be little link between the frequency and magnitude of price changes – prices that change less frequently do not tend to change by more. Fifth, the strongest correlation between price and volume changes is contemporaneous, suggesting that prices and volumes move together from week to week. And sixth, rough analysis based on simplifying assumptions suggests that consumers are fairly price sensitive: volumes change by more than prices.

What lies beneath: what can disaggregated data tell us about the behaviour of prices?

This paper uses a factor-augmented vector autoregression technique to examine the role that macroeconomic and sector-specific factors play in UK price fluctuations at the aggregate and disaggregated levels. Macroeconomic factors are less important for disaggregated prices than aggregate ones. There also appears to be significant aggregation bias - the persistence of aggregate inflation series is much higher than the underlying persistence across the range of disaggregated price series. Our results suggest that monetary policy affects relative prices in the short to medium term, and that the degree of competition within industries plays a role in determining pricing behaviour.

UK Business Investment: Long-Run Elasticities and Short-Run Dynamics

Theory tells us that output, the capital stock and the user cost of capital are related. From the capital accumulation identity, it also follows that the capital stock and investment have a long-run proportional relationship. The dynamic structure thus implies a multi-cointegrating framework, in which separate cointegrating relationships are identifiable. This has been used to justify the estimation of investment equations embodying a reduced-form long-run relationship between investment and output (rather than between the capital stock and output). In this paper, a new investment equation is estimated in the full structural framework, exploiting a measure of the capital stock constructed by the Bank, and a long series for the cost of capital. A CES production function is assumed, and a well-determined estimate of the elasticity of substitution is obtained by a variety of measures. The robust result is that the elasticity of substitution is significantly different from unity (the Cobb-Douglas case), at about 0.45. Overidentifying restrictions on the long-run relationship are all accepted. Although the key long-run parameter (the elasticity of substitution) is highly robust to alternative specifications, single-equation investment relationships may obscure the dynamics. There is evidence that the Johansen method is oversized, but given this, a test for excluding the capital accumulation identity from the investment equation is much better than using a single-equation ECM.

Elasticities, markups and technical progress: evidence from a state-space approach

Conventional techniques for estimating the elasticity of substitution between capital and labour in the production process typically focus on factor-demand equations. An implicit assumption in this approach is normally that the markup is stationary. But that may not be true. This paper considers a new approach that models the markup as an unobserved variable. Using the factor-demand equations for capital and labour, technical progress can also be estimated as a stochastic process, rather than just imposing a time trend. The resulting estimates of the whole-economy markup for the UK economy suggest that it has fallen over the past 30 years, and this result appears to withstand a variety of robustness checks. The estimated elasticity is somewhat lower than most previous estimates. This implies that conventional techniques may be misleading.

How Do Individual UK Consumer Prices Behave

This paper examines the behaviour of individual consumer prices in the United Kingdom, and uncovers a number of stylised facts about pricing behaviour. First, on average 19% of prices change each month, although this falls to 15% if sales are excluded. Second, the probability of price changes is not constant over time. Third, goods prices change more frequently than services prices. Fourth, the distribution of price changes is wide, although a significant number of changes are relatively small and close to zero. Fifth, prices that change more frequently tend to do so by less. We find that conventional pricing theories struggle to match these results, particularly the marked heterogeneity, which argues against the use of ‘representative agent’ models.

The Effect of Quantitative Easing on Capital Markets

Quantitative Easing (QE) has seemingly been the (monetary) policy instrument of choice in advanced economies since the financial crisis and global recession broke. But the impact on capital markets remains highly contentious. This paper reviews evidence on the impact of QE so far, and considers potential risks that may have arisen from its application.

Should UK House Prices Rise in Line with Earnings

House prices are a constant source of fascination and discussion in the UK. In the short term, prices move closely with market conditions. Over the longer term, meanwhile, attention often focuses on simple ratios of house prices to earnings. Despite this, relatively little work has been done to assess the sustainable long-term trend in house prices – and, in particular, how the sustainable ratio of house prices to earnings may have evolved over time. As such, this paper examines the behaviour of house prices in the context of the past forty years of spending patterns, finding that consumer preferences are such that the equilibrium ratio of house prices to earnings may well have risen over time.