The economic benefits of membership are among the main reasons the Czech Republic and other Central and Eastern European countries sought to join the EU. These benefits included greater opportunities for trade and investment within the integrated single market, and access to potentially lucrative EU subsidies, such as those provided by the CAP and the structural funds. EU accession also posed an economic challenge for the CEECs, however, as they had to adopt stringent and often costly EU rules and regulations, and they have had to cope with increased competitive pressures within the single market. Both the economic benefits and challenges of EU accession were magnified for countries making the painful transition from communism to capitalism and the market economy. For these countries, integration into the EU single market began well before the actual date of accession, although the process of economic adaptation and change did not end there.