Who Said or What Said? Estimating Ideological Bias in Views Among Economists

There exists a long-standing debate about the influence of ideology in economics. Surprisingly, however, there is no concrete empirical evidence to examine this critical issue. Using an online randomized controlled experiment involving economists in 19 countries, we examine the effect of ideological bias on views among economists. Participants were asked to evaluate statements from prominent economists on different topics, while source attribution for each statement was randomized without participants’ knowledge. For each statement, participants either received a mainstream source, an ideologically different less-/non-mainstream source, or no source. We find that changing source attributions from mainstream to less-/non-mainstream, or removing them, significantly reduces economists’ reported agreement with statements. Using a model of Bayesian updating we examine two competing hypotheses as potential explanations for these results: unbiased Bayesian updating versus ideologically-biased Bayesian updating. While we find no evidence in support of unbiased updating, our results are consistent with biased Bayesian updating. More specifically, we find that changing/removing sources (1) has no impact on economists’ reported confidence with their evaluations; (2) similarly affects experts/non-experts in relevant areas; and (3) affects those at the far right of the political spectrum much more significantly than those at the far left. Finally, we find significant heterogeneity in our results by gender, country, PhD completion country, research area, and undergraduate major, with patterns consistent with the existence of ideological bias

New paleo- and rockmagnetic results from La Chaine des Puys during the Laschamp event : Evidences of mineralogical disturbances

Thermoluminescence, présenté par J.P. Valet, abstracts bookForty years ago Bonhommet and Babkine (in 1967) reported on two lava flows(Laschamp and Olby) and a scoria cone (Laschamp) from the Chaîne des Puys with almost reversed directions of magnetization which were interpreted as the record of a geomagnetic excursion named after the Laschamp village. Due to specific magnetic mineralogy, these rocks were shown to be prone to self-reversals, potentially misrecording the ambient magnetic field during their emplacement. This new discovery raised a controversy regarding the origin of the directions recorded by these lava flows. Many studies were then conducted to determine the age of the event at 40 ka, which coincides with a period of low dipole field intensity and thus a high probability to observe significant departures of the field from the axial dipolar direction. Taking advantage of new Potassium-argon age determinations, we revisited some sites and sampled several new ones in order to clarify the origin of their magnetization and hopefully improve the resolution of the Laschamp event. This study involves thermal and alternating field demagnetization of 257 samples from 20 units, including 12 new localities, and also experiments of magnetic mineralogy (susceptibility as a function of temperature, thermomagnetic curves, IRM acquisition curves and hysteresis parameters determination). The magnetic mineralogy is dominated by primary titanomagnetite with a Curie temperature of 130±60°C (0.

Origin and age of the directions recorded during the Laschamp event in the Chaine des Puys (France)

International audienc

Magnetic exchange bias of more than 1 Tesla in a natural mineral intergrowth

Magnetic exchange bias is a phenomenon whereby the hysteresis loop of a 'soft' magnetic phase is shifted by an amount HE along the applied field axis owing to its interaction with a 'hard' magnetic phase. Since the discovery of exchange bias fifty years ago1, the development of a general theory has been hampered by the uncertain nature of the interfaces between the hard and soft phases, commonly between an antiferromagnetic phase and a ferro- or ferrimagnetic phase. Exchange bias continues to be the subject of investigation because of its technological applications and because it is now possible to manipulate magnetic materials at the nanoscale2, 3, 4, 5, 6. Here we present the first documented example of exchange bias of significant magnitude (>1 T) in a natural mineral. We demonstrate that exchange bias in this system is due to the interaction between coherently intergrown magnetic phases formed through a natural process of phase separation during slow cooling over millions of years. Transmission electron microscopy studies show that these intergrowths have a known crystallographic orientation with a known crystallographic structure and that the interfaces are coherent

Low-temperature exchange coupling between Fe[sub 2]O[sub 3] and FeTiO[sub 3]: Insight into the mechanism of giant exchange bias in a natural nanoscale intergrowth

Exchange bias 1 T at 10 K has been observed in natural sample of Fe2O3 containing abundant nanoscale exsolution lamellae of FeTiO3. Exchange bias is first observed below the Néel temperature of FeTiO3 55 K. Possible interface magnetic structures are explored within the framework of a classical Heisenberg model using Monte Carlo simulations. The simulations predict a threshold value of the Fe2O3 anisotropy constant, below which Fe3+ spins become tilted out of the basal plane in the vicinity of the interfaces. This tilting creates a c-axis component of magnetization in the Fe2O3 host that couples to the c-axis magnetization of the FeTiO3 lamellae. Exchange interactions across the interfaces are frustrated when the FeTiO3 lamellae contain an even number of Fe2+ layers, resulting in zero net exchange bias. Lamellae containing an odd number of Fe2+ layers, however, are negatively exchange coupled to the Fe2O3 host across both 001 bounding surfaces, and are the dominant source of exchange bias. Exchange bias is observed whenever there is a significant c-axis component to both the Fe2O3 magnetization and the applied field. An exchange bias of 0.9 T was obtained with an anisotropy constant of 0.1 K

Determinants of Access to Credit for Corporate Farms in Russia

Access to agricultural credit is analysed using logit regression for a sample of corporate farms included in the 2003 BASIS survey. As is normal in market economies, more profitable farms have a higher probability of borrowing from financial institutions. On the other hand, contrary to the pattern in market economies, asset endowments (land and capital stock) have a very weak effect on the ability to borrow, reflecting the low collaterisability of farm assets in Russia. Overdue debt does not significantly restrict the ability to borrow in our analysis, presumably because of the general acceptance of soft budget constraints in the system. Comparative Economic Studies (2005) 47, 181–187. doi:10.1057/palgrave.ces.8100083