I'm not sure how you are classifying consulting firms. Firms like Charles River and Navigant offer a more niche type of service with a focus on economics. There is a group of economic consulting firms, including Analysis Group, The Brattle Group, Cornerstone, and others that shouldn't be considered second tier. These firms all recruit highly quantitative students from top programs with strong academic credentials and offer compensation at levels similar to the management consulting firms. These firms are not as widely known to the general public as they often perform behind the scenes, but all provide opportunities to work on high profile and challenging projects, and often with top tier academics. While this type of consulting isn't for everyone (most undergraduate hires at such firms work for 2-3 years before heading to graduate school), it shouldn't be thought of as "second tier."