Brown et al. (1983) noted that time series studies to that point had found that for a 10 percent increase in the minimum wage, there was a decrease in teenage employment of 1–3 percent. However, the studies found wider variation, from 0 to over 3 percent, in their estimates for the effect on teenage unemployment (teenagers without a job and looking for one). In contrast to the simple supply and demand diagram, it was commonly found that teenagers withdrew from the labor force in response to the minimum wage, which produced the possibility of equal reductions in the supply as well as the demand for labor at a higher minimum wage and hence no impact on the unemployment rate. Using a variety of specifications of the employment and unemployment equations (using ordinary least squares vs. generalized least squares regression procedures, and linear vs. logarithmic specifications), they found that a 10 percent increase in the minimum wage caused a 1 percent decrease in teenage employment, and no change in the teenage unemployment rate. The study also found a small, but statistically significant, increase in unemployment for adults aged 20–24.