The Antebellum American South experienced rapid biological innovation centered around an active market for new cotton seed varieties, despite the absence of intellectual property rights. ...Contemporaries complained new seed was initially offered at high prices, which subsequently collapsed. Using local newspaper evidence, this paper documents this market’s operation. It then rationalizes the price movements given the potential of improved seed to multiply at finite rates. The initial prices were sufficiently high to provide meaningful incentives to innovate. This study also identifies information problems affecting the cotton seed market, leading observers to claim too many new varieties were released, not too few.
Historical Presidential Betting Markets Rhode, Paul W.; Strumpf, Koleman S.
The Journal of economic perspectives,
04/2004, Volume:
18, Issue:
2
Journal Article
Peer reviewed
Open access
This paper analyzes the large and often well-organized markets for betting on U.S. presidential elections that operated between 1868 and 1940. Four main points are addressed. First, we show that the ...market did a remarkable job forecasting elections in an era before scientific polling. Second, the market was fairly efficient, despite the limited information of participants and active attempts to manipulate the odds. Third, we argue political betting markets disappeared largely because of the rise of scientific polls and the increasing availability of other forms of gambling. Finally, we discuss lessons this experience provides for the present.
Full text
Available for:
BFBNIB, CEKLJ, INZLJ, IZUM, KILJ, NMLJ, NUK, ODKLJ, PILJ, PNG, SAZU, UL, UM, UPUK, ZRSKP
A semi-analytical model is presented that describes the temporal development of a blazar synchrotron flare for the case of a broadband synchrotron power spectrum. We examine three different injection ...scenarios and present its influence on the synchrotron flare. An accurate approximation of the half-life of a synchrotron flare is analytically computed and we give some illustrative examples of the time evolution of the emergent synchrotron intensity by using a numerical integration method. The synchrotron flare starts at all photon energies right after the injection of ultrarelativistic electrons into the spherical emission volume of radius R and its duration exceeds the light travel time 2R/c in the low energy regime. Furthermore, the flare duration extends by the period of injection of relativistic electrons into the emission knot. However, the energetic and spatial distribution of these injected electrons has no significant influence on the flare duration. We obtain a temporal behavior that agrees most favorably with the observations of PKS 2155-304 on 2006 July 29-30 and it differs considerably from the results that were recently achieved by using a monochromatic approximation of the synchrotron power.
The literature on the Dust Bowl conveys the impression of widespread exodus from the Great Plains. But farm populations were often more resilient than the iconic photographs of the era suggest. While ...recent studies highlight that tenacity, less is known about the process of recovery and postwar growth. This paper offers a window on both. The evidence discussed here survives as a legacy of a long-lived, state-run agricultural statistics program in Kansas. The State Board of Agriculture conducted annual household surveys of farms between 1873 and 1981. Linked together over time, these farm-level surveys offer a detailed record of the residential and land-use histories of three communities, and they begin to illustrate how farm households met the challenges of the drought years and adjusted to the new agriculture in the post–World War II era.
Full text
Available for:
BFBNIB, INZLJ, NMLJ, NUK, PNG, UL, UM, UPUK, ZRSKP
During the nineteenth century, U.S. manufacturers shifted away from the “hand labor” mode of production, characteristic of artisan shops, to “machine labor,” which was increasingly concentrated in ...steam-powered factories. This transition fundamentally changed production tasks, jobs, and job requirements. This paper uses digitized data on these two production modes from an 1899 U.S. Commissioner of Labor report to estimate the frequency and impact of the use of inanimate power on production operation times. About half of production operations were mechanized; the use of inanimate power raised productivity, accounting for about one-quarter to one-third of the overall productivity advantage of machine labor. However, additional factors, such as the increased division of labor and adoption of high-volume production, also played quantitatively important roles in raising productivity in machine production versus by hand.
The First G-APD Cherenkov Telescope (FACT) demonstrates the usability of novel Geiger-mode operated Avalanche Photo Diodes (G-APD, often called SiPM) for Imaging Atmospheric Cherenkov Telescopes ...(IACT). The camera consists of 1440pixels with dedicated electronics operating at 2 Giga samples per second. It is installed on the refurbished HEGRA telescope with a mirror area of ≈9.5m2 on the Canary Island La Palma. FACT is taking data almost every night since the camera was installed in October 2011. It was possible to improve the data taking efficiency to very high values due to the very stable and reliable operation. This also allows to operate FACT remotely without any need for operators on site. Even remote human intervention became less and less frequent over the years, allowing operation to become mostly automatic. FACT is monitoring the long-term behavior of some very-high energy variable extra-galactic sources with unparalleled sampling density as well as testing the behavior of the sensors under severe weather conditions. Due to the long exposure of FACT's G-APDs under strong moonlight conditions it was possible to evaluate the aging effects of G-APDs due to collected charge. No indication of aging was found. No external calibration device is needed to operate FACT since the properties of the sensors themselves allow for a high precision self-calibration of the camera.
•SiPMs show no sign of ageing in 5years of operation.•High precision self calibration is possible without external calibration device.•Very high data taking efficiency has been reach due to excessive automation.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Basilar membrane (BM) responses to two types of broadband stimuli-clicks and Schroeder-phase complexes--were recorded at several sites at the base of the chinchilla cochlea. Recording sites ...(characteristic frequency, CF, in the range of 5.5-18 kHz) span the 1-4-mm basal region of the basilar membrane. BM responses to clicks consisted of undamped oscillations with instantaneous frequency that increased over time until it reached a value around CF. The time constant of this glide is CF dependent. Throughout the entire region under study, BM vibration exceeded umbo motion by up to 60 dB. Nonlinear properties of BM responses to clicks resemble those found in the more studied 8-10-kHz region. Amplitude spectra of Schroeder-phase complex stimuli, which consist of a series of sinusoidal components summed in negative (-SCHR) and positive Schroeder phase (+SCHR), are flat. The envelope of BM responses to +SCHR stimuli contains valleys, or dips, that are wider than those found in responses to the -SCHR stimuli. Hence, BM responses to the former stimuli are "peakier" than responses to the latter. Differences in response waveforms are less obvious in linear cochleae. Suppression of a near-CF tone by -SCHR stimuli was larger than that evoked by +SCHR stimuli.
1. Amplitude modulation (AM) is a pervasive property of acoustic communication systems. In the present study we investigate neural temporal mechanisms in the auditory nerve and cochlear nuclei of the ...pentobarbital sodium-anesthesized cat associated with the neural coding of 100% AM tones, both in quiet and in the presence of wideband, quasi-flat-spectrum noise. The AM carrier frequency was set to the neuron's characteristic frequency (CF) and the sound pressure level (SPL) of acoustic stimuli was varied over a wide dynamic range of intensities (< or = 40 dB). The temporal AM-encoding capability of auditory neurons was measured by computing the synchronization coefficient (SC) of the neural response to the signal's modulation and carrier frequency. The temporal modulation transfer function (tMTF) of a neuron was then computed by measuring the SC of the response to signals of variable fmod (50-2550 Hz). 2. Neurons in the cochlear nuclei synchronize on average more highly to the modulation frequency than fibers of comparable CF, threshold, and spontaneous rate in the auditory nerve. The disparity in performance is greatest at high SPLs and low signal-to-noise ratios. However, there is a significant degree of diversity in AM-encoding capability among neurons in both the cochlear nuclei and auditory nerve. Among auditory nerve fibers (ANFs), low- and medium-spontaneous-rate (SR) units (SR < 18 spike/s) phase-lock with greater precision than comparable high-SR units at any given frequency, particularly at moderate to high SPLs, consistent with previous studies. 3. The phase-locking capabilities of neurons in the cochlear nucleus are considerably more variable than in the auditory nerve. Moreover, the variability itself depends on two distinct measures of phase-locking performance. Most ANFs are capable of phase-locking to frequencies as high as 3-4 kHz. In the cochlear nucleus many unit types do not phase-lock to modulation frequencies > 1 kHz. As a result, phase-locking performance is measured on the basis of two parameters, maximum synchronization, irrespective of stimulus frequency, and the upper frequency limit for significant phase-locking. 4. Cochlear nucleus neurons may be divided into three distinct groups on the basis of maximum synchronization capability. In group 1 are the primary-like (PL) units of the anteroventral division, whose phase-locking capabilities are comparable with those of high-SR ANFs.
PDF
