Management consulting firms primarily focus on helping businesses improve their performance by providing recommendations to address business challenges. This may involve looking into a division that is not profitable and/or deciding which factory to close down.
Economic consulting, on the other hand, focuses on the intersection of business, economics, and law. One type of project may involve two (or more) companies where one is accused of causing economic harm to the other and we are asked to measure the damages. In another, we may be asked to forecast current and/or future liabilities stemming from an environmental product liability. Another could focus on determining if price movements were consistent with an alleged manipulative scheme in an energy market.