In the past, the major part of the chain of manufacturing and services used to be located in a given country, which meant that, from the monetary policy perspective, the domestic demand was of great importance, and in particular — the size of output in relation to its potential level i.e. the so-called output gap. The impact of the global economy, on the other hand, was observed mainly due to changes in the terms-of-trade i.e. the ratio of export to import prices, which in turn was affected by, among others, commodity prices and changes in external demand. Nowadays, inter alia as a result of globalisation of production and services, the role of the domestic output gap in explaining inflation has decreased significantly, as shown by the BIS research 6 . As in the case of the model applied by the NBP in forecasting inflation, the role of the output gap as a factor that determines inflation is much smaller than it used to be. In old books on macroeconomics inflation is treated largely as a local development, i.e. dependent in a great measure on domestic factors (such as the domestic output gap and inflation expectations). Today, inflation is becoming increasingly less local, and in turn, becomes more and more dependent on global factors, i.e. the relationship between global demand to global supply. Research that analysed the course of inflation in 22 OECD countries between 1960 and 2003 has shown that 70% of inflation volatility may be explained by a common factor 7 .
Number of work permits in the UK, Ireland and Sweden issued to citizens of new Member States following the EU accession In thousands UK *  Ireland**  Sweden***  Total  In % of workforce †  Lithuania  44.72  26.37  0.37  71.46  4.4  Latvia  23.03  12.94  0.16  36.14  3.2  Estonia  4.68  3.39  0.36  8.43  1.3  Poland  204.90  70.14  2.16  277.20  1.6  Czech Republic  20.01  6.39  0.07  26.47  0.5  Hungary  10.35  3.83  0.20  14.37  0.3  Slovakia  36.36  10.93  0.09  47.38  1.8  *Source: Accession Monitoring Reports, http://www.ind.homeoffice.gov.uk. The data include the period between May 2004 and December 2005. NBP calculations. **Source: Skills needs in the Irish economy: The role of migration, A submission by the Expert Group on Future Skills Needs and Forfás to the Minister for Enterprise, Trade & Employment, http://www.skillsireland.ie. The data include the period between May 2004 and August 2005. ***Source: Migracje specjalistów wysokiej klasy w kontekście członkostwa Polski w Unii Europejskiej. Centre for Migration Research, Warsaw University. The data include the period between May 2004 and December 2004. †Workforce – people of 15 and more years of age in Q1, 2004. 10  HSBC “The Great Migration. How China’s 200 million new workers will change the economy forever”, HSBC Global Research, October 2005.