independent federal agency that provides official macroeconomic and industry statistics, says "the often-cited identification of a recession with two consecutive quarters of negative GDP growth is not an official designation" and that instead, "The designation of a recession is the province of a committee of experts at the National Bureau of Economic Research". The European Union adopted a definition similar to that of the NBER, using GDP alongside additional macroeconomic variables such as employment and other measures to assess the depth of decline in economic activity. Recessions in the United Kingdom are generally defined as two consecutive quarters of negative economic growth, as measured by the seasonal adjusted quarter-on-quarter figures for real GDP. The Organisation for Economic Co-operation and Development (OECD) defines a recession as a period of at least two years during which the cumulative output gap reaches at least 2% of GDP, and the output gap is at least 1% for at least one year. Attributes A recession has many attributes that can occur simultaneously and includes declines in component measures of economic activity (GDP) such as consumption, investment, government spending, and net export activity. These summary measures reflect underlying drivers such as employment levels and skills, household savings rates, corporate investment decisions, interest rates, demographics, and government policies. Economist Richard C. Koo wrote that under ideal conditions, a country's economy should have the household sector as net savers and the corporate sector as net borrowers, with the government budget nearly balanced and net exports near zero. A severe (GDP down by 10%) or prolonged (three or four years) recession is referred to as an economic depression, although some argue that their causes and cures can be different. As an informal shorthand, economists sometimes refer to different recession shapes, such as V-shaped, U-shaped, L-shaped and W-shaped recessions. Type of recession or shape The type and shape of recessions are distinctive. In the US, v-shaped, or short-and-sharp contractions followed by rapid and sustained recovery, occurred in 1954 and 1990–1991; U-shaped (prolonged slump) in 1974–1975, and W-shaped, or double-dip recessions in 1949 and 1980–1982. Japan's 1993–1994 recession was U-shaped and its 8-out-of-9 quarters of contraction in 1997–1999 can be described as L-shaped. Korea, Hong Kong and South-east Asia experienced U-shaped recessions in 1997–1998, although Thailand's eight consecutive quarters of decline should be termed L-shaped. Psychological aspects Recessions have psychological and confidence aspects. For example, if companies expect economic activity to