Intra- and Inter-sectoral Knowledge Spillovers and TFP Growth Rates

In this paper I estimate unobserved labor-generated knowledge spillovers within and among six large macroeconomic sectors covering the totality of the US civilian economy from 1948 to 1991. Unobserved spillovers are identified by observed TFP changes measured using Dale Jorgenson’s quality-adjusted factor and product panel data. I construct a series of sectoral knowledge spillover matrices that show that changes in the magnitude and direction of spillovers are associated to the productivity slowdown in the US economy of the early seventies. These matrices also allow me to compute the gap between the market and the optimal allocation of labor among sectors. Moreover, I show that sectoral market wages do not capture the totality of spillovers and I measure the difference. My measurement of spillovers shows that from 1948 to 1991 manufacturing generated knowledge for all sectors, being overall the main engine of growth. Using Samuel Kortum’s data on patent production and use in the U.S. I find that sectoral labor generated knowledge flows coincide with the sectoral patterns of other, disembodied information flows. I also find the productivity slowdown coincides with a change in the pattern of generation and diffusion of spillovers. In the mid seventies manufacturing initiates its decline as the engine of growth and trade starts to catch up as the main generator of knowledge spillovers to the economy; simultaneously, the relative weight of all intra-sectoral spillovers diminishes in favor of spillovers between sectors. Finally, I find that the market allocates resources inefficiently, as spillovers are measured to be significant. More resources should go to the main spillover generating sector, that is, manufacturing, so that employment in this sector increases by 32%, and output by 8%; and wages increase in all sectors, except for services and mining.Knowledge Spillovers, Productivity

Topological and symmetry broken phases of Z_N parafermions in one dimension

We classify the gapped phases of Z_N parafermions in one dimension and construct a representative of each phase. Even in the absence of additional symmetries besides parafermionic parity, parafermions may be realized in a variety of phases, one for each divisor n of N. The phases can be characterized by spontaneous symmetry breaking, topology, or a mixture of the two. Purely topological phases arise if n is a unitary divisor, i.e. if n and N/n are co-prime. Our analysis is based on the explicit realization of all symmetry broken gapped phases in the dual Z_N-invariant quantum spin chains.Comment: 16 pages; v2: improved exposition and additional reference

Knowledge Spillovers and TFP Growth Rates

In this paper I calibrate unobserved labor-generated knowledge spillovers within and between six large macroeconomic sectors covering the U.S. civilian economy from 1948 to 1991. Using quality-adjusted data I show that manufacturing and trade & transportation are the main source of knowledge flows to the overall economy for the entire period. However, the productivity slowdown of the early seventies coincides with trade & transportation taking over manufacturing as the main source and destination of post-73 knowledge flows. Furthermore, I compute the gap between the market and the optimal allocation of labor across sectors, and the wedge between market and optimal wages by sector. I find that, for the whole period, optimal employment in manufacturing and trade & transportation is, respectively, 20% and 27% above market. As a result optimal output in these sectors is 12% and 16% higher than the market’s, and optimal wages in manufacturing are 54% above market wages.Knowledge spillovers; productivity; human capital; learning; wages.

Infinite Matrix Product States for long range SU(N) spin models

We construct 1D and 2D long-range SU(N) spin models as parent Hamiltonians associated with infinite matrix product states. The latter are constructed from correlators of primary fields in the SU(N) level 1 WZW model. Since the resulting groundstates are of Gutzwiller-Jastrow type, our models can be regarded as lattice discretizations of fractional quantum Hall systems. We then focus on two specific types of 1D spin chains with spins located on the unit circle, a uniform and an alternating arrangement. For an equidistant distribution of identical spins we establish an explicit connection to the SU(N) Haldane-Shastry model, thereby proving that the model is critical and described by a SU(N) level 1 WZW model. In contrast, while turning out to be critical as well, the alternating model can only be treated numerically. Our numerical results rely on a reformulation of the original problem in terms of loop models.Comment: 37 pages, 6 figure

An algorithm for twisted fusion rules

We present an algorithm for an efficient calculation of the fusion rules of twisted representations of untwisted affine Lie algebras. These fusion rules appear in WZW orbifold theories and as annulus coefficients in boundary WZW theories; they provide NIM-reps of the WZW fusion rules.Comment: 8 page

Occupational Selection in Multilingual Labor Markets: The Case of Catalonia

In multilingual labor markets agents with high proficiency in more than one language may be selected into occupations that require high levels of skill in communicating with customers or writing reports in more than one language. In this paper we measure this effect in Catalonia, where two languages, Catalan and Spanish, coexist. Using census data for 1991 and 1996, and controlling for endogeneity of Catalan knowledge, we find that proficiency in speaking, reading, and writing Catalan reinforces selection into being employed, being an entrepreneur, and into white-collar occupations and communication-intensive jobs. In particular, being able to read and speak Catalan increases the probability of selection into white collar occupations by betwen 9 and 14 percentage points, while writing Catalan increases by 6 to 13 percentage points the probability of engaging in services, and government and educational activities.Language, Occupational Selection, Industry, Immigration, Skill Premium.

Occupational Selection in Multilingual Labor Markets

In multilingual labor markets agents with high proficiency in more than one language may be selected into occupations that require high levels of skill in communicating with customers or writing reports in more than one language. In this paper we measure this effect in Catalonia, where two languages, Catalan and Spanish, coexist. Using census data for 1991 and 1996, and controlling for endogeneity of Catalan knowledge, we find that proficiency in speaking, reading and writing Catalan reinforces selection into communication intensive jobs/positions such as entrepreneurial, trade, and service activities; white-collar occupations; and permanent employment. Interestingly, the effect of language on occupational selection is stronger for women than for men.occupational selection, language, labor markets