Economic Returns to Social Capital in the Urban Informal Sector in Developing Countries: Micro Evidence from Small Textile Producers in Bolivia

The paper uses micro-level data obtained from surveying informal and formal small textile producers in Bolivia to estimate the economic returns to social capital. Social capital is defined as being linked to other individuals. The paper studies forms of social links that vary with respect to their inclusiveness and their ability to enforce cooperation. The paper shows, first, that social capital has an economic return for informal firms but not for formal ones. Informal firms operate without the shadow of courts in an environment that is characterized by a lack of anonymous trust which makes self-enforcing social links valuable. Second, more inclusive social capital generates a higher return as long as the self-enforcement constraint is met. The evidence supports the hypothesis that the “strength of weak ties”- argument advanced by scholars such as Granovetter, Putnam, and Fukuyama has to be complemented by the game-theoretic condition requiring exchange among linked players to be (self)-enforceable.Social Capital, Anonymous Trust, Informal Sector, Small Firms.

Method for measuring pollutant formation

Diagnostic methods for determining an instantaneous rate of pollutant formation in a combustion system are based on measurement of chemiluminescence intensity generated simultaneously with the formation of the pollutant. The chemiluminescent signal is generated by an analog reaction which occurs in parallel with a key step in the formation of a specific pollutant of interest. The connection between the analog reaction and the pollution reaction is such that the chemiluminescent signal indicates the local, instantaneous formation rate of the pollutant of interest

Gas temperature measurements using the dual-line detection Rayleigh scattering technique

A new laser-induced Rayleigh scattering method is presented for the improved temperature diagnostics of gas flows. In the present technique, the two lines of a copper vapor laser are used to obtain the time and space resolved temperature. A single set of optics is used to form the optical probe and to collect the signal simultaneously from both the 510 nm and the 578 nm lines. The dual-line detection allows for the determination and removal of surface-scattered laser light from a Rayleigh signal thereby improving the applicability of Rayleigh scattering to near wall flows with a high degree of glare. An optical system using the dual-line detection technique is built, calibrated and tested in a hot air jet under various levels of background contamination. The results indicate that highly accurate temperature measurements are possible even when the laser-line background intensity, captured by the collecting optics, is five times that of the Rayleigh signal

Dual-Line Detection Rayleigh Scattering Measurements of Density and Temperature

Measurements of the laser Rayleigh scattering signal in a flow to determine density and temperature have been commonly employed in open flames and in wind tunnel environments. In these measurements, the density or reciprocal temperature is correlated with the Rayleigh scattering signal intensity. A major advantage of Rayleigh scattering for these applications is the simple experimental arrangement allowed by this technique. Intensity-based Rayleigh scattering measurements of density and temperature have been limited to relatively clean flows in open environments so that interference from particle scattering and laser scattering is minimal. A new approach, using dual-line detection Rayleigh (DLDR) scattering extends the applicability of Rayleigh scattering measurements of density and temperature to enclosed environments where surface scattering interference is high. Depending on particle size and optical properties, this approach may also reduce interference from particle scattering

HP-filter for Java

Java implementation of the Hodrick-Prescott filter

HP-Filter DLL executable

Set of files used to implement dynamic link libraries for the Hodrick-Prescott filter.

HP-Filter Excel Add-In

Set of files to implement the Hodrick-Prescott filter in Excel

Band-Pass Filter Excel Add-in

Set of files allowing to extract trend from a series using the band-pass filter