Mario Draghi is an Italian banker and economist who succeeded Jean-Claude Trichet as President of the European Central Bank on 1 November 2011.

The Consumer Price Index (CPI) measures the change in the price of goods and services from the perspective of the consumer. It is a key way to measure changes in purchasing trends and inflation.

A higher than expected reading should be taken as positive/bullish for the GBP, while a lower than expected reading should be taken as negative/bearish for the GBP.

CPI assesses changes in the cost of living by measuring changes consumer pay for a set of items. CPI serves as the headline figure for inflation. Simply put, inflation reflects a decline in the purchasing power of the dollar, where each dollar buys fewer goods and services. In terms of measuring inflation, CPI is the most obvious way to quantify changes in purchasing power. The report tracks changes in the price of a basket of goods and services that a typical American household might purchase. An increase in the Consumer Price Index indicates that it takes more dollars to purchase the same set basket of basic consumer items.

Inflation is generally bad news for the economy, causing instability, uncertainty and hardship. To address inflation, the Fed may raise interest rates. However, the Fed relies on the PCE Deflator as its primary gauge of inflation because the CPI does not account for the ability of consumer to substitute out of CPI's set. Price changes tend to cause consumers to switch from buying one good to a less expensive-other, a tendency that the fixed-basket CPI figure does not yet account for. Given that the PCE Deflator is a more comprehensive calculation, based on changes in consumption; it is the figure the Fed prefers.

The figure is released monthly, as either a month over month annualized percentage change, or percentage change for the full year. The figure is seasonally adjusted to account seasonal consumption patterns.Inflation is generally bad news for the economy, causing instability, uncertainty and hardship. To address inflation, the Fed may raise interest rates. However, the Fed relies on the PCE Deflator as its primary gauge of inflation because the CPI does not account for the ability of consumer to substitute out of CPI's set. Price changes tend to cause consumers to switch from buying one good to a less expensive-other, a tendency that the fixed-basket CPI figure does not yet account for. Given that the PCE Deflator is a more comprehensive calculation, based on changes in consumption; it is the figure the Fed prefers.

The figure is released monthly, as either a month over month annualized percentage change, or percentage change for the full year. The figure is seasonally adjusted to account seasonal consumption patterns.

In the United Kingdom, the Retail Prices Index or Retail Price Index (RPI) is a measure of inflation published monthly by the Office for National Statistics.

A monthly survey that measures change in input prices as incurred by UK manufacturers. Input prices include the cost of materials used plus operation costs of running the business. The index can be used as a measure of inflation, given that higher input costs will likely be passed on from producers to consumers in the form of higher retail prices.

The headline is the percentage change in the Producer Price Index (Input) from the previous quarter and previous year.

A monthly survey that measures the price changes of goods produced by UK manufacturers. The figure is also known as "Factory Gate Price" because it usually matches the price of goods when they first leave the factory. Increased prices in manufacturing typically lead to higher retail prices for consumers. However, it is also likely that higher output prices are caused by manufacturers charging a higher premium due to higher demand for their goods. Consequently, market trends in consumption should be considered with Output PPI to avoid data misinterpretation.

A broad measure of the movement of single-family house prices. Apart from serving as an indicator of house price trends, the House Price Index (HPI) provides an analytical tool for estimating changes in the rates of mortgage defaults, prepayments and housing affordability. It is a weighted, repeat-sales index, which means that it measures average price changes in repeat sales or refinancings on the same properties.

Gauge for goods sold at retail outlets in the past month. Retail Sales is a leading indicator for the economy. Rising consumer spending fuels economic growth, confirms signals from consumer confidence, and may spark inflationary pressures.

The headline figure is expressed as the percentage change from the same month last year.

John C. Williams is President and CEO of the Federal Reserve Bank of San Francisco.