A representative salary

Ezra Klein, following a suggestion by Rep. Jim Cooper, asks whether members of Congress should be paid according to their performance. Since the base salary of a representative is, for the vast majority of representatives (and nearly all Senators), mostly a symbolic gift anyways, I see no reason why it ought not be made even more symbolic. Rather than tying their salaries to the vocational aspects of their work, however (committees attended, hands shook, constituent letters robo-signed), why not tie their compensation to the ‘stock price’ of the nation, as it were? I’ve always thought that Congressional salaries should be coupled with the nation’s median income—perhaps 1.5 or 1.7 times the median income would be an appropriate salary. Alternatively, we could choose a basket of national performance measures—education, crime, environmental health, income mobility, research productivity, and so on—and link salaries to that.