guest: so, latino is not a race category. so we have separate statistics in terms of hispanics. because as an hispanic, you can be either white or black nor other. here, and probably reflects or asian. host: one of the other things that we were discussing earlier was -- or that brian brought up wages. this is what you have found. do you know members make more money than others in similar fields? guest: so if you take a look at the chart for 2014, the difference is not hundred dollars for union members, $714 for not union -- nonunion workers. this reflects what we call the median. sort of the middleware, if you will. but it also affects a great many other aspects that you need to take into account. for example, the age distribution of union members may be different than nonunion. they tend to be older. and earnings do tend to increase with age. it also reflects industry composition. for example, there is a lot of workers that are in food accommodation, but he is asian -- unionization rate there tends to be very low. host: lydia depillis, what is a closed shop? guest: a closed sho