. all of these methods offer different means of teasing out information, and making robust inferences, in situations where empirical relationships may be complex, non - linear and evolving and where data may be arriving at different frequencies and in different formats. these approaches differ significantly from classical econometric techniques for inference and testing often used in economics and finance. this revolution in data provision, and in techniques to understand it, offers analytical riches. mining those riches requires, however, considerable care. for example, issues of data privacy loom much larger with granular, in some cases personalised, data. these issues have, rightly, risen in prominence recently. at the same time as putting it to use, safeguarding big data is a key preoccupation of the bank in its research. the promise of big data to the extent big data can be characterised, this is usually done using the “ three v ’ s ” : volume, velocity and variety. using the three v as an organising framework, let me discuss some examples of how these data moore ( 1965 ) noted the annual doubling in the number of components per integrated circuit. sintef ( 2013 ). ericsson mobility report see https : / / www. statista. com / chart / 10913 / number - of - photos - taken - worldwide / using dataset in turrell et al ( forthcoming ). dwoskin ( 2015 ). the true number of data scientists worldwide is highly uncertain. many individuals work on data science without necessarily using that job title, but the opposite is also true. chakraborty and joseph ( 2017 ). bholat et al ( 2015 ). all speeches are available online at www. bankofengland. co. uk / speeches and techniques have been used in recent bank research to improve our understanding of the functioning of the economy and financial system. volume th the statistical bedrock of macro - economic analysis, since at least the middle of the 20 century, has been the national accounts. the national accounts have always relied on an eclectic range of data. in the past, manor accounts on land use, crops and livestock were used to estimate agricultural output. industrial production was measured by sources as varied as numbers of iron blast furnaces and books listed by the british library. and services output was estimated based on merchant shipping tonnage. with more data than ever coming on stream, that use of new and eclectic data sources and methods is, if anything, gaining further ground within statistical agencies.

prices alone explains more than half of the headline inflation figure. in the medium term, it is critical whether rising energy prices will increase inflation expectations and wages or change firms'pricing behaviour. energy inflation and supply chain bottlenecks alone would not lead to a sustained acceleration in inflation unless there are major second round effects, leading to a wage - price spiral. unlike in the united states, with its labour market red hot, wage inflation in the euro area has been rather moderate – until recently, that is. we have seen clear signs of acceleration in the first months of this year. that ’ s why we must be mindful of not letting inflation expectations become unanchored, which would be very damaging to price stability. this is now the single most critical factor in determining the course of monetary policy. last december, the ecb governing council started the gradual process of monetary policy normalisation. and we have been fortunate to have our renewed monetary policy strategy in place as we face the current turmoil. the ecb strategy review was a critical turning point in ecb monetary policy. it was the final step in the process of making the ecb a modern central bank since mario draghi ’ s “ whatever it takes ” speech. the ultimate reason for the strategy review was the emergence of profound structural changes in the euro area and the world economy. these include the change in the relationship between the spare capacity of the economy and inflation, the fall in natural interest rates, and sluggish productivity growth. according to the revised strategy, price stability – the primary objective of the ecb – is best maintained by aiming for 2 % inflation over the medium term. the inflation target is symmetric : the governing council considers both inflation above and below this 2 % target to be equally undesirable. the new strategy was worked out in 2020 – 21 in a disinflationary, even deflationary environment, and it serves to ensure that the economy does not get stuck in a situation of too slow inflation for a prolonged period. the governing council also stated that inflation may also be temporarily moderately above the target. the medium - term orientation of monetary policy allows for a better emphasis in decision - making on other objectives that are important for all euro area countries, such as full employment, without, of course, jeopardizing price stability. i tell you this also to illustrate how quickly the operating environment of monetary policy has changed. it was still less than a year ago, i recall, that some commentators