Biofuels are a renewable alternative for reducing the climate impact of transport. Due to the versatility of biomass and complexity of economics and impacts, biofuels are part of a complex system, which is here analysed from a systems perspective. Several models are developed in order to assess...

We study the effect of spatial inequality on economic activity. Given that the relationship is highly simultaneous in nature, we use exogenous variation in geographic features to construct an instrument for spatial inequality, which is independent from any man-made factors. Inequality measures...

The commonly-used satellite images of nighttime lights fail to capture the true brightness of most cities. We show that night lights are a reliable proxy for economic activity at the city level, provided they are first corrected for top-coding. We present a stylized model of urban luminosity and...

We use transaction-level data to study changes in the concentration of US imports. Concentration has fallen in the typical industry, while it is stable by industry and origin country. The fall in concentration is driven by the extensive margin: the number of exporting firms has grown, and the...

Trade costs are crucial in new economic geography (NEG) models. The unavailability of actual trade costs data requires the approximation of trade costs. Most NEG studies do not deal with the ramifications of the particular trade costs specification used. This paper shows that the specification...

We use worldwide satellite data to analyse how population size and density affect urban pollution. We find that density significantly increases pollution exposure. Looking only at urban areas, we find that population size affects exposure more than density. Moreover, the effect is driven mostly...