He's wrong to say that the study only looks at employment status. It looks at income and a number of other factors as well (mainly, income and time spent working).
However, he is right that the article's conclusion is mis-represented:
"Overall, we don’t find much evidence in favor of a negative correlation between income and shopping time, particularly comparison shopping possibly motivated by locating better prices. As a matter of fact, whereas total time spent purchasing goods and services is about 20 minutes per day, the component of shopping time devoted to comparing prices and products seems to be extremely low in the data. It is about 4 seconds a day on average, given the large number of respondents declaring zero. Moreover, nonparticipants and the employed spent more time than the unemployed in this activity. This may indicate that most of the effort made by consumers in the goods market is unrelated to uncovering better prices."
He's wrong to say that the study only looks at employment status. It looks at income and a number of other factors as well (mainly, income and time spent working).
However, he is right that the article's conclusion is mis-represented:
"Overall, we don’t find much evidence in favor of a negative correlation between income and shopping time, particularly comparison shopping possibly motivated by locating better prices. As a matter of fact, whereas total time spent purchasing goods and services is about 20 minutes per day, the component of shopping time devoted to comparing prices and products seems to be extremely low in the data. It is about 4 seconds a day on average, given the large number of respondents declaring zero. Moreover, nonparticipants and the employed spent more time than the unemployed in this activity. This may indicate that most of the effort made by consumers in the goods market is unrelated to uncovering better prices."