However, we assume that households will choose to spread consumption over time, so that the saving ratio will continue to fall in spite of an increase in interest rates. Housing construction activity is still high. In January and February, housing starts were 17.5 per cent higher than in the same period last year. Growth in housing investment is expected to ease through 2005. However, the projection for housing starts is also very high for 2005. Such a high level of housing starts over several years probably means that more dwellings will be constructed than implied by underlying demand. As a result, housing investment is expected to decline after a period. Higher interest rates and weaker developments in the Norwegian economy may also lead to a fall in residential construction after a period. The rise in house prices has moderated, and prices in March were 8.2 per cent higher than in the same month last year. The upturn in mainland fixed investment is broadly based. Stronger profitability, higher capacity utilisation and solid export growth will contribute to continued investment growth in goods-producing industries. Demand for services is expected to continue to grow for a period ahead with an attendant increase in investment in service sectors. When growth in the economy gradually slows, investment growth will probably slacken. Mainland exports of goods and services will also benefit from solid global growth this year. Later in the period, a continued loss of market shares as a result of high cost levels will dampen export growth.
3  According to the Food Outlook from the Food and Agricultural Organization of the United Nations (FAO), 22 May 2008. BIS Review 68/2008  3  When we decide on the future direction of monetary policy, it is important to know whether the rising oil and food prices will have lasting or temporary effects on inflation. 4 It is difficult to know this in advance. We must follow developments closely. But we can receive some guidance by looking at the factors that lie behind the price increases. Increased demand, supply effects and portfolio investment behind rising commodity prices One reason for the high commodity prices is the increased demand in the world market from emerging economies. Higher incomes per capita in China, India and other rapidly growing economies have led to increased demand for food and also to changes in the patterns of food consumption. Demand for meat has increased in particular, which has in turn pushed up the demand for and prices of feed grain. This also spreads to other food crops. It is reasonable to believe that the demand for food in the world will remain high. Another important driving force behind the world demand for commodities is the investment in ethanol and biodiesel in recent years. The increased use of some food commodities in the production of biofuels limits the supply of food and increases the price of food crops.