Using the data set "state data.dta" (which is available on the textbook's web site at www.cambridge.org/fpsr), we estimated a two-variable regression model using data from each US state and the District of Columbia with per capita income ("pcinc" in our data set) as our dependent variable and the percent- age of state residents with a college degree ("pctba" in our data set) as the independent variable. The estimated equation was:

pcinci = 11519.78 + 1028.96pctbai.

Interpret the parameter estimate for the effect of a state's level of education on average income levels.