Do Vietnamese upland farmers benefit from high world market prices for maize?

For rural households in the north of Vietnam, maize cropping is the main source of income. In the face of the world market price increases of the recent past, we analyze the regional marketing chain of this commodity qualitatively and econometrically investigating to what extent smallholder farmers in developing countries are affected by international price movements. Vietnamese maize markets are found to be well integrated. Recent price hikes have fully transmitted along the regional supply chain so that farmers profited. Nevertheless, adverse factors such as increasing input prices have neutralized these benefits resulting in a decline in real income of smallholders.     

Risk management strategies - before Hominization and after

Selected examples, ranging from birds to pastoralistic nomads and subsisting peasants, indicate that the higher animals adopt foraging strategies similar to individual decision makers in economies without market (subsistence economies): in contrast to actors in (ideal neoclassical) market economies, maximizing expected utility, they operate in such way as to optimize long-term survival of genetically related groups. This can be seen as a strategy of (maximum) ruin avoidance, played by 'selfish genes'. In the sense of conjectural history the parallelism between risk behaviour of animals and early men may be regarded as the continued existence of principles of natural evolution beyond hominization up to the historical emergence of complex societies where pursuit of surplus production replaced ruin avoidance as the primary orientation in the older subsistence economies.     

Emerging risk of autoignition and fire in underground coal storage

The risk and prevention of autoignition in underground coal storage facilities are reviewed in the light of the recent incidents of smouldering fires. Also, the opportunities are considered on the efficiency of the alternatives to prevent and extinguish closed-space fires. The complexities in avoiding and extinguishing underground fires are highlighted in the case example, describing the observations and outcome of a smouldering coal fire in the storage. The principles of self-heating and most critical factors in spontaneous combustion such as the condition and quality of coal are fairly well known, but usually only provide partial help in fire prevention. The documented cases and the case example suggest that nitrogen injection can be useful for extinguishing controllable fires. Three-phase foams and oxygen-displacing exhaust gases appear preferable against uncontrolled fires, particularly if access to the fire area is limited or impossible. Otherwise, efficient fire extinction during power plant operation can be challenging, as any air ingress tends to feed the fire and results in losses of the extinguishing agent and the heating value of coal. Methods and indicators for detecting and predicting the ignition are discussed, and improvements are suggested to enhance the storage and plant availability.     

Innovation timing games: a general framework with applications

We offer a new algorithm for analyzing innovation timing games. Its main advantage over the traditional approach is that it applies to problems that had previously been intractable. We use the algorithm to examine two classical innovation problems. We find that the competition takes the form of a waiting game with a second-mover advantage either for any level of R&D costs (process innovation) or for high R&D costs (product innovation). Moreover, both models predict that the second-mover advantage is monotonically increasing in the costs of R&D.     

Is self-employment really a bad experience? : The effects of previous self-employment on subsequent wage-employment wages

We use propensity score matching methods to quantify the effects of past self-employment experience on subsequent earnings in dependent employment using data on the population of Danish men observed between 1990 and 1996. Our results generally confirm existing studies in that we find that a spell of self-employment is associated with lower hourly wages compared to workers who were consecutively wage-employed. We also show, however, that this effect disappears—and even becomes positive in some settings—for formerly self-employed who find dependent employment in the same sector as their self-employment sector. Hence, the on average negative effect of self-employment is rather caused by sector switching than by the self-employment experience per se. Moreover, formerly self-employed who either enjoyed a high income or hired at least one worker during their self-employment spell receive wages in subsequent dependent employment that are at least as high as for individuals who have been consecutively wage-employed.