Investment and Instability

Although recent research has repeatedly found a negative association between investment and political instability, the existence and direction of causality between these two variables has not yet been investigated. This paper empirically tests for a causal and negative long-run relationship between political instability to investment. It finds that there is a robust causal relation from instability to investment, and that it is positive. In other words, an increase in political instability Granger causes an increase in investment. We identify three different theories that can explain this result.http://deepblue.lib.umich.edu/bitstream/2027.42/39721/3/wp337.pd

Who is Afraid of Political Instability?

An unstable macroeconomic environment is often regarded as detrimental to economic growth. Among the sources contributing to such instability, the literature has assigned most of the blame to political issues. This paper empirically tests for a causal and negative long-term relation between political instability and economic growth, but finds no evidence of such a relationship. Sensitivity analysis indicates that there is a contemporaneous negative relationship and that, in the long run and ignoring institutional factors, the Sub-Saharan Africa group plays the determining role in steering this relationship into causal and negative.http://deepblue.lib.umich.edu/bitstream/2027.42/39710/3/wp326.pd

WHO IS AFRAID OF POLITICAL INSTABILITY?

An unstable macroeconomic environment is often regarded as detrimental to economic growth. Among the sources contributing to such instability, much of the blame has been assigned to political issues. This paper empirically tests for a causal and negative long-run relationship between political instability and economic growth but finds no such relationship. Sensitivity analysis, however, indicates that there is indeed a short-run negative relationship and, that in the long-run and ignoring institutional factors, the group of African countries is the driving force. In other words, we suspect that excluding the African countries from their samples, results of a negative relation between SPI and growth would founder.Economic growth, Political instability, Granger causality

Who is Afraid of Political Instability?

An unstable macroeconomic environment is often regarded as detrimental to economic growth. Among the sources contributing to such instability, the literature has assigned most of the blame to political issues. This paper empirically tests for a causal and negative long-term relation between political instability and economic growth, but finds no evidence of such a relationship. Sensitivity analysis indicates that there is a contemporaneous negative relationship and that, in the long run and ignoring institutional factors, the Sub-Saharan Africa group plays the determining role in steering this relationship into causal and negative.economic growth, political instability

Investment and Instability

Although recent research has repeatedly found a negative association between investment and political instability, the existence and direction of causality between these two variables has not yet been investigated. This paper empirically tests for a causal and negative long-run relationship between political instability to investment. It finds that there is a robust causal relation from instability to investment, and that it is positive. In other words, an increase in political instability Granger causes an increase in investment. We identify three different theories that can explain this result.political instability, aggragate investment, Granger causality

Investment and Instability

Although recet research has repeatedly found a negative association between investment and socio-political instability (SPI), the existence and direction of causality between these two variables has not yet been investigated. We construct an index of SPI for non-overlaping five-years periods between 1960 and 1995 for a sample of 98 developing countries. We use the Granger causality framework and report Anderson-Hsiao- Arellano instrumental variable estimates. Our main finding is that, for the full sample, there is a robust causal relationship going from SPI to investment, and it is positive. In other words, we find three reasons may explain this result: one is that SPI delays investment, another is that it destroys at least part of the capital stock, and the third is that SPI causes changes in government and in government policies that are benefical in the long run.Political instability, Aggregate investment, Granger causality

Domains of invasion organelle proteins from apicomplexan parasites are homologous with the Apple domains of blood coagulation factor XI and plasma pre-kallikrein and are members of the PAN module superfamily

AbstractMicronemes are specialised organelles, found in all apicomplexan parasites, which secrete molecules that are essential for parasite attachment to and invasion of host cells. Regions of several microneme proteins have sequence similarity to the Apple domains (A-domains) of blood coagulation factor XI (FXI) and plasma pre-kallikrein (PK). We have used mass spectrometry on a recombinant-expressed, putative A-domain from the microneme protein EtMIC5 from Eimeria tenella, to demonstrate that three intramolecular disulphide bridges are formed. These bridges are analogous to those that stabilise A-domains in FXI and PK. The data confirm that the apicomplexan domains are structural homologues of A-domains and are therefore novel members of the PAN module superfamily, which also includes the N-terminal domains of members of the plasminogen/hepatocyte growth factor family. The role of A-domains/PAN modules in apicomplexan parasites is not known, but their presence in the microneme suggests that they may be important for mediating protein–protein or protein–carbohydrate interactions during parasite attachment and host cell invasion

High Redshift Supernovae in the Hubble Deep Field

Two supernovae detected in the Hubble Deep Field using the original December 1995 epoch and data from a shorter (63000 s in F814W) December 1997 visit with HST are discussed. The supernovae (SNe) are both associated with distinct galaxies at redshifts of 0.95 (spectroscopic) from Cohen etal. (1996) and 1.32 (photometric) from the work of Fernandez-Soto, Lanzetta, and Yahil (1998). These redshifts are near, in the case of 0.95, and well beyond for 1.32 the greatest distance reported previously for SNe. We show that our observations are sensitive to SNe to z < 1.8 in either epoch for an event near peak brightness. Detailed simulations are discussed that quantify the level at which false events from our search phase would start to to arise, and the completeness of our search as a function of both SN brightness and host galaxy redshift. The number of Type Ia and Type II SNe expected as a function of redshift in the two HDF epochs are discussed in relation to several published predictions and our own detailed calculations. A mean detection frequency of one SN per epoch for the small HDF area is consistent with expectations from current theory.Comment: 62 pages, 17 figures, ApJ 1999 in pres

Diversity of Decline-Rate-Corrected Type Ia Supernova Rise Times: One Mode or Two?

B-band light-curve rise times for eight unusually well-observed nearby Type Ia supernovae (SNe) are fitted by a newly developed template-building algorithm, using light-curve functions that are smooth, flexible, and free of potential bias from externally derived templates and other prior assumptions. From the available literature, photometric BVRI data collected over many months, including the earliest points, are reconciled, combined, and fitted to a unique time of explosion for each SN. On average, after they are corrected for light-curve decline rate, three SNe rise in 18.81 +- 0.36 days, while five SNe rise in 16.64 +- 0.21 days. If all eight SNe are sampled from a single parent population (a hypothesis not favored by statistical tests), the rms intrinsic scatter of the decline-rate-corrected SN rise time is 0.96 +0.52 -0.25 days -- a first measurement of this dispersion. The corresponding global mean rise time is 17.44 +- 0.39 days, where the uncertainty is dominated by intrinsic variance. This value is ~2 days shorter than two published averages that nominally are twice as precise, though also based on small samples. When comparing high-z to low-z SN luminosities for determining cosmological parameters, bias can be introduced by use of a light-curve template with an unrealistic rise time. If the period over which light curves are sampled depends on z in a manner typical of current search and measurement strategies, a two-day discrepancy in template rise time can bias the luminosity comparison by ~0.03 magnitudes.Comment: As accepted by The Astrophysical Journal; 15 pages, 6 figures, 2 tables. Explanatory material rearranged and enhanced; Fig. 4 reformatte

The Rise Times of High and Low Redshift Type Ia Supernovae are Consistent

We present a self-consistent comparison of the rise times for low- and high-redshift Type Ia supernovae. Following previous studies, the early light curve is modeled using a t-squared law, which is then mated with a modified Leibundgut template light curve. The best-fit t-squared law is determined for ensemble samples of low- and high-redshift supernovae by fitting simultaneously for all light curve parameters for all supernovae in each sample. Our method fully accounts for the non-negligible covariance amongst the light curve fitting parameters, which previous analyses have neglected. Contrary to Riess et al. (1999), we find fair to good agreement between the rise times of the low- and high-redshift Type Ia supernovae. The uncertainty in the rise time of the high-redshift Type Ia supernovae is presently quite large (roughly +/- 1.2 days statistical), making any search for evidence of evolution based on a comparison of rise times premature. Furthermore, systematic effects on rise time determinations from the high-redshift observations, due to the form of the late-time light curve and the manner in which the light curves of these supernovae were sampled, can bias the high-redshift rise time determinations by up to +3.6/-1.9 days under extreme situations. The peak brightnesses - used for cosmology - do not suffer any significant bias, nor any significant increase in uncertainty.Comment: 18 pages, 4 figures, Accepted for publication in the Astronomical Journal. Also available at http://www.lbl.gov/~nugent/papers.html Typos were corrected and a few sentences were added for improved clarit