In Boston, 140 people are willing to spend an hour working as personal trainers for an hourly wage of $10. For each additional $5 that the wage increases above $10, an additional 35 people are willing to spend an hour working. For hourly wages of $10, $15, $20, $25, and $30, plot the daily labor supply curve for personal trainers on the following graph. Supply 0 35 70 105 140 175 210 245 280 315 350 50 45 40 35 30 25 20 15 10 5 0 WAGE (Dollars per hour) LABOR (Number of workers) What is one explanation for why this labor supply curve is upward sloping? Wages have to increase to accommodate union pressure. Labor production functions exhibit diminishing marginal returns. People prefer to spend time doing leisure activities rather than working. The opportunity cost of leisure decreases as wages decrease