Feature-tracking techniques are employed to investigate why there is a relative minimum in storminess during winter within the Pacific storm track (the midwinter suppression). It is found that the frequency and amplitude of disturbances entering the Pacific storm track from midlatitude Asia are substantially reduced during winter relative to fall and spring and that the magnitude of this reduction is more than sufficient to account for the midwinter supression. Growth rates of individual disturbances are calculated and compared to expectations from linear theory for several regions of interest. Although there are discrepancies between linear expectations and observed growth rates over the Pacific, the growth of disturbances within the Pacific storm track cannot explain why the midwinter suppression exists. Furthermore, it is determined that the development of a wintertime reduction in storminess over midlatitude Asia is consistent with linear expectations, which predict a wintertime minimum in Eady growth rates in this region, mainly because of increased static stability. Several other mechanisms that may contribute to the initiation of the midwinter suppression over midlatitude Asia are discussed,including the interaction between upper-level waves and topography, the behavior of waves upwind of the Tibetan Plateau, and the initiation of lee cyclones.

Accumulating evidence suggests that agricultural production could be greatly affected by climate change, but there remains little quantitative understanding of how these agricultural impacts would affect economic livelihoods in poor countries. Here we consider three scenarios of agricultural impacts of climate change by 2030 (impacts resulting in low, medium, or high productivity) and evaluate the resulting changes in global commodity prices, national economic welfare, and the incidence of poverty in a set of 15 developing countries. Although the small price changes under the medium scenario are consistent with previous findings, we find the potential for much larger food price changes than reported in recent studies which have largely focused on the most likely outcomes. In our low productivity scenario, prices for major staples rise 10-60% by 2030. The poverty impacts of these price changes depend as much on where impoverished households earn their income as on the agricultural impacts themselves, with poverty rates in some non-agricultural household groups rising by 20-50% in parts of Africa and Asia under these price changes, and falling by equal amounts for agriculture-specialized households elsewhere in Asia and Latin America. The potential for such large distributional effects within and across countries emphasizes the importance of looking beyond central case climate shocks and beyond a simple focus on yields - or highly aggregated poverty impacts.

Norway has made a point of administering its petroleum resources using three distinct government bodies: a national oil company (NOC) engaged in commercial hydrocarbon operations; a government ministry to help set policy; and a regulatory body to provide oversight and technical expertise.  In Norway's case, this institutional design has provided useful checks and balances, helped minimize conflicts of interest, and allowed the NOC, Statoil, to focus on commercial activities while other government agencies regulate oil operators including Statoil itself.  Norway's relative success in managing its hydrocarbon resources has prompted development institutions to consider whether this "Norwegian Model" of separated government functions should be recommended to other oil-producing countries, particularly those whose oil sectors have underperformed. 

Seeking insight into this question, we study eight countries with different political and institutional characteristics, some of which have attempted to separate functions in oil in the manner of Norway and some of which have not.  We conclude that while the Norwegian Model may be a "best practice" of sorts, it is not the best prescription for every ailing oil sector.  The separation of functions approach is most useful and feasible in cases where political competition exists and institutional capacity is relatively strong.  Unchallenged leaders, on the other hand, are often able to adequately discharge commercial and policy/regulatory functions in the oil sector using the same entity, although this approach may not be robust against political changes (nor do we address in this paper any possible development or human welfare implications of this arrangement). 

When technical and regulatory talent is particularly lacking in a country, better outcomes may result from consolidating commercial, policy, and regulatory functions in a single body until institutional capacity has further developed.  Countries like Nigeria with vibrant political competition but limited institutional capacity pose the most significant challenge for oil sector reform: unitary control over the sector is impossible but separation of functions is often impossible to implement.  In such cases reformers are wise to focus on incremental but sustainable improvements in technical and institutional capacity.

There is widespread interest in the impacts of climate change on agriculture in Sub-Saharan Africa (SSA), and on the most effective investments to assist adaptation to these changes, yet the scientific basis for estimating production risks and prioritizing investments has been quite limited. Here we show that by combining historical crop production and weather data into a panel analysis, a robust model of yield response to climate change emerges for several key African crops. By mid-century, the mean estimates of aggregate production changes in SSA under our preferred model specification are - 22, - 17, - 17, - 18, and - 8% for maize, sorghum, millet, groundnut, and cassava, respectively. In all cases except cassava, there is a 95% probability that damages exceed 7%, and a 5% probability that they exceed 27%. Moreover, countries with the highest average yields have the largest projected yield losses, suggesting that well-fertilized modern seed varieties are more susceptible to heat related losses.