The origins of meso economics: Schumpeter's legacy and beyond

The paper starts from Schumpeter's proposition that entrepreneurs carry out innovations (the micro level), that swarms of followers imitate them (meso) and that, as a consequence, ‘creative destruction' leads to economic development ‘from within' (macro). It is argued that Schumpeter's approach can be developed into a new—more general—micro-meso-macro framework in economics. Center stage is meso. Its essential characteristic is bimodality, meaning that one idea (the generic rule) can be physically actualized by many agents (a population). Ideas can relate to others, and, in this way, meso constitutes a structure component of a ‘deep' invisible macro structure. Equally, the rule actualization process unfolds over time—modelled in the paper as a meso trajectory with three phases of rule origination, selective adoption and retention—and here meso represents a process component of a visible ‘surface' structure. The macro measure with a view to the appropriateness of meso components is generic correspondence. At the level of ideas, its measure is order; at that of actual relative adoption frequencies, it is generic equilibrium. Economic development occurs at the deep level as transition from one generic rule to another, inducing a change of order, and, at the surface level, as the new rule is adopted, destroying an old equilibrium and establishing a new on

The patterns of output growth of firms and countries: new evidence on scale invariances and scale specificities

This work brings together two distinct pieces of evidence concerning, at the macro level, international distributions of incomes and their dynamics, and, at the micro level, the size distributions of firms and the properties of their growth rates. First, our empirical analysis provides a new look at the international distribu- tions of incomes and growth rates by investigating more closely the relationship between the two entities and the statistical properties of the growth process. Second, we identify the statistical properties that are invariant with respect to the scale of observation (country or firm) as distinct from those that are scale specific. This exercise proposes a few major interpretative challenges regarding the correlating processes underlying the statistical evidence.International distribution of income, international growth rates, firm growth, scaling laws, growth volatility, exponential tails

Income Levels and Income Growth. Some New Cross-Country Evidence and Some Interpretative Puzzles

This work brings together two distinct ensembles of evidence concerning, at macro level, international distributions of incomes and their dynamics, and, at micro level, the size distributions of firms and the properties of their growth rates. Together, we also consider an intermediate level of observation, namely the properties of sectoral growth. First, our empirical analysis provides a fresh look at the international distri-butions of incomes and growth rates by investigating more closely the relationship between the two entities and the statistical properties of the growth process. Second, we try to identify those statistical properties which are invariant with respect to the scale of observation (country, sector or firm) as distinct from those that are instead scale specific. This exercise puts forward a few major interpretative challenges regarding the correlating processes underlying the statistical evidence.International Distribution of Incomes, International Growth Rates, Scaling Laws, Growth Volatility, Exponential Tails

The sequential twinning-transformation induced plasticity effects in a thermomechanically processed high Mn austenitic steel

Different initial microstructures with various bimodal grain size distributions (BGSD) were produced in a high Mn austenitic steel through applying a predetermined set of thermomechanical processing cycles. The corresponding room temperature mechanical properties and the related strain hardening behaviors were assessed using tensile testing method. The results indicated that in the microstructure with high grain size bimodality, the length and amplitude of rapid hardening region was well higher than the others. This was attributed to its higher capability to a'-martensite formation. In addition, the threshold strain to initiate martensitic transformation was shifted to the lower one in the microstructure with higher bimodal grain size distribution. The latter was related to the lower arisen back stresses in the interior regions of the coarser grains. Furthermore, different transformation paths were identified as the BGSD changed. The austenite could directly transform to a'-martensite (¿a') in the microstructure with lower BGSD; in this case the a'-martensite mainly appeared at the intersections of deformation twins. In contrast, in microstructures with higher BGSD, the nucleation occurred at the intersections of e-martensite platelets. The co-existence of these transformation paths provided an extended transformation induced plasticity effect ending to a higher elongation to fracture in the course of deformation. In order to summarize the contribution of various strain hardening mechanisms, a deformation map was also constructed. Accordingly, the enhanced ductility/strength properties were attributed to the sequential operation of extended transformation induced plasticity and twinning induced plasticity effects.Peer ReviewedPostprint (author's final draft

The Distribution of the Size of Price Changes

Different theories of price stickiness have distinct implications on the number of modes in the distribution of price changes. We formally test for the number of modes in the price change distribution of 36 supermarkets, spanning 22 countries and 5 continents. We present results for three modality tests: the two best-known tests in the statistical literature, Hartigan's Dip and Silverman's Bandwidth, and a test designed in this paper, called the Proportional Mass test (PM). Three main results are uncovered. First, when the traditional tests are used, unimodality is rejected in about 90 percent of the retailers. When we used the PM test, which reduces the impact of smaller modes in the distribution and can be applied to test for modality around zero percent, we still reject unimodality in two thirds of the supermarkets. Second, category-level heterogeneity can account for about half of the PM test's rejections of unimodality. Finally, a simulation of the model in Alvarez, Lippi, and Paciello (2010) shows that the data is consistent a combination of both time and state-dependent pricing behaviors.

Selection mechanisms affect volatility in evolving markets

Financial asset markets are sociotechnical systems whose constituent agents are subject to evolutionary pressure as unprofitable agents exit the marketplace and more profitable agents continue to trade assets. Using a population of evolving zero-intelligence agents and a frequent batch auction price-discovery mechanism as substrate, we analyze the role played by evolutionary selection mechanisms in determining macro-observable market statistics. In particular, we show that selection mechanisms incorporating a local fitness-proportionate component are associated with high correlation between a micro, risk-aversion parameter and a commonly-used macro-volatility statistic, while a purely quantile-based selection mechanism shows significantly less correlation.Comment: 9 pages, 7 figures, to appear in proceedings of GECCO 2019 as a full pape

Mesoscale movement and recursion behaviors of Namibian black rhinos.

Background:Understanding rhino movement behavior, especially their recursive movements, holds significant promise for enhancing rhino conservation efforts, and protecting their habitats and the biodiversity they support. Here we investigate the daily, biweekly, and seasonal recursion behavior of rhinos, to aid conservation applications and increase our foundational knowledge about these important ecosystem engineers. Methods:Using relocation data from 59 rhinos across northern Namibia and 8 years of sampling efforts, we investigated patterns in 24-h displacement at dawn, dusk, midday, and midnight to examine movement behaviors at an intermediate scale and across daily behavioral modes of foraging and resting. To understand recursion patterns across animals' short and long-term ranges, we built T-LoCoH time use grids to estimate recursive movement by each individual. Comparing these grids to contemporaneous MODIS imagery, we investigated productivity's influence on short-term space use and recursion. Finally, we investigated patterns of recursion within a year's home range, measuring the time to return to the most intensively used patches. Results:Twenty four-hour displacements at dawn were frequently smaller than 24-h displacements at dusk or at midday and midnight resting periods. Recursion analyses demonstrated that short-term recursion was most common in areas of median rather than maximum NDVI values. Investigated across a full year, recursion analysis showed rhinos most frequently returned to areas within 8-21 days, though visits were also seen separated by months likely suggesting seasonality in range use. Conclusions:Our results indicate that rhinos may frequently stay within the same area of their home ranges for days at a time, and possibly return to the same general area days in a row especially during morning foraging bouts. Recursion across larger time scales is also evident, and likely a contributing mechanism for maintaining open landscapes and browsing lawns of the savanna