Why the aggregate supply curve slopes upward in the short runIn the short run, the quantity of output that firms supply can deviate from the natural level of output if the actual price level in the economy deviates from the expected price level. Several theories explain how this might happen. For example, the sticky-wage theory asserts that output prices adjust more quickly to changes in the price level than wages, in part because of long-term wage contracts. Suppose a firm signs a contract agreeing to pay its workers $15 per hour for the next year, based on an expected price level of 100. If the actual price level turns out to be 110, the firm's output prices willrise , and the wages the firm pays its workers will remain fixed at the contracted level. The firm will respond to the unexpected increase in the price level byincreasing the quantity of output it supplies. If many firms face similarly rigid wage contracts, the unexpected increase in the price level causes the quantity of output supplied torise above the natural level of output in the short run. Suppose the economy's short-run aggregate supply (AS) curve is given by the following equation:The Greek letter alpha represents a number that determines how much output responds to unexpected changes in the price level. In this case, assume that alpha = $2 billion. That is, when the actual price level exceeds the expected price level by 1, the quantity of output supplied will exceed the natural level of output by $2 billion. Suppose the natural level of output is $50 billion of real GDP and that people expect a price level of 110.On the following graph, use the purple line (diamond symbol) to plot this economy's long-run aggregate supply (LRAS) curve. Then use the orange line segments (square symbol) to plot the economy's short-run aggregate supply (AS) curve at each of the following price levels: 100, 105, 110, 115, and 120.The short-run quantity of output supplied by firms will fall below the natural level of output when the actual price level (rise above/ falls below) the price level that people expected.