Structural change in a multi-sector model of growth

We study a multisector model of growth with differences in TFP growth rates across sectors and derive sufficient conditions for the coexistence of structural change, characterized by sectoral labor reallocation and balanced aggregate growth. The conditions are weak restrictions on the utility and production functions. Along the balanced growth path, labor employed in the production of consumption goods gradually moves to the sector with the lowest TFP growth rate, until in the limit it is the only sector with nontrivial employment of this kind. The employment shares of intermediate and capital goods remain constant during the reallocation process

The connection between non-exponential relaxation and fragility in supercooled liquids

Among the outstanding problems in the theory of supercooled liquids are the reasons for the rapid increase in their viscosity and relaxation times as the temperature is lowered towards the glass transition temperature, the non-exponential time dependence of the relaxation, and the possible connection between these two properties. The ferromagnetic Potts model on a square latice is a simple system that is found to exhibit these properties. Our calculations show that in this system the connection between them is associated with the dependence on temperature and time of the average environment of the sites. Some of the consequences of this for understanding the behavior of supercooled liquids are discussed.Comment: 12 pages, 8 figure

Gaussian density fluctuations, mode coupling theory, and all that

We consider a toy model for glassy dynamics of colloidal suspensions: a single Brownian particle diffusing among immobile obstacles. If Gaussian factorization of static density fluctuations is assumed, this model can be solved without factorization approximation for any dynamic correlation function. The solution differs from that obtained from the ideal mode coupling theory (MCT). The latter is equivalent to including only some, positive definite terms in an expression for the memory function. An approximate re-summation of the complete expression suggests that, under the assumption of Gaussian factorization of static fluctuations, mobile particle's motion is always diffusive. In contrast, MCT predicts that the mobile particle becomes localized at a high enough obstacle density. We discuss the implications of these results for models for glassy dynamics.Comment: to be published in Europhys. Let

Structural change in a multi-sector model of growth.

We study a multisector model of growth with differences in TFP growth rates across sectors and derive sufficient conditions for the coexistence of structural change, characterized by sectoral labor reallocation and balanced aggregate growth. The conditions are weak restrictions on the utility and production functions. Along the balanced growth path, labor employed in the production of consumption goods gradually moves to the sector with the lowest TFP growth rate, until in the limit it is the only sector with nontrivial employment of this kind. The employment shares of intermediate and capital goods remain constant during the reallocation process.

Trends in hours and economic growth.

We study long-run trends in market hours of work and employment shifts across economic sectors driven by uneven TFP growth in market and home production. We focus on the structural transformation between agriculture, manufacturing and services and on the marketization of home production. The model can rationalize the observed falling or Ushaped pattern for aggregate hours, the shift from agriculture to services and balanced aggregate growth. We find support for the model’s predictions in long-run US data.

In brief: Hot and cold seasons in the housing market

The difference in the price you pay for the same house in the summer and in the winter is huge, according to Rachel Ngai and Silvana Tenreyro.

Hot and Cold Seasons in the Housing Market

Every year during the second and thirdquarters (the "hot season") housing markets in the UK and the US experience systematic above-trend increases in both prices and transactions. During the fourth and first quarters (the "cold season"), house prices and transactions fall below trend. We propose a search-and-matching framework that sheds new light on the mechanisms governing housing market fluctuations. The model has a "thick-market" effect that can generate substantial differences in the volume of transactions and prices across seasons, with the extent of seasonality in prices depending crucially on the bargaining power of sellers. The model can quantitatively mimic the seasonal fluctuations in transactions and prices observed in the UK and the US.housing market, thick-market effects, search-and-matching, seasonality, house price fluctuations