Middle Stone Age Technology and Cultural Evolution at Magubike Rockshelter,Southern Tanzania

This paper contributes new information to the body of evidence for Middle Stone Age tool-use in Tanzania. Magubike rockshelter is located in an archaeologically unexplored region of the south-central part of the country, and thus fills a significant geographical gap between sites further to the north and those to the south in Zambia and Mozambique. Early analysis of a portion of the lithic materials demonstrates parallel changes in lithic reduction intensity, raw material preference and typology. This article explores possible explanations for this pattern, including the possibility that they reflect changes to local environment, and suggests avenues for future research.     

Balancing Multiple Goals: Analyzing Votes on Free Trade Agreements in the U.S. House of Representatives

Despite increasing polarization in the House of Representatives, preferential trade agreements (PTAs) often pass not only with, but often because of, support from both parties. What explains these patterns? When do members cross party lines to support (or oppose) trade legislation? We argue that members are both ideologically and electorally motivated. Further, we argue that the relative balance of these incentives varies across the membership in meaningful ways. We examine House votes on 11 PTAs and find that ideology and district trade position have independent effects on support for free trade. We also find that the effect of trade position is conditioned by the ideology of the legislator; moderates are more responsive to their constituents' interests on trade.