Editorial Favoritism in Economics?

Are articles by authors with institutional connections or personal ties to the publishing journal's editor(s)/coeditors of lower quality than those authored without such connections? Examination of articles published in six core economics journals in 1990 found that articles authored by those with such connections, especially service on the publishing journal's editorial board, are statistically and numerically of higher quality than articles by those without such connections. In addition, this quality difference does not decrease over time.