Constructing Krinsky and Robb Confidence Interval for Mean and Median WTP Using Stata

The ultimate goal of most non-market valuation studies is to obtain welfare measures i.e. mean and/or median willingness to pay (WTP) and confidence intervals. While the delta (nlcom) and bootstrap (bs) methods can be used for constructing such confidence intervals in Stata, they are not recommended because WTP measures are non-linear functions of random parameters (Creel and Loomis, 1991). The best and widely used approach, which is not available in Stata, consists in simulating the confidence intervals using the Krinsky and Robb procedure (Haab and McConnell, 2002). Hole (2007) has recently introduced a useful command, wtp, which implements the Krinsky and Robb procedure in Stata, but does not feature mean and median WTP estimates and their confidence intervals. I present a Stata command, wtpcikr, which computes mean and median WTP, confidence intervals using the Krinsky and Robb procedure, achieved significance level (ASL) for testing the null hypothesis that WTP equals zero, and a relative efficiency measure (Loomis and Ekstrand, 1998). The command supports both linear and exponential contingent valuation models estimated with or without covariates using the Stata commands probit, logit, biprobit, and xtprobit. I will illustrate the use of wtpcikr by replicating empirical results in Haab and McConnell (2002).

Debt Deception: How Debt Buyers Abuse the Legal System to Prey on Lower-Income New Yorkers

In this report, we examine lawsuits filed by debt buyers and their profound impact on low- and moderate-income New Yorkers, lower-income communities, and communities of color. We begin, in Part I, with background on the debt buying industry, including an analysis of the debt buyer business model and collection methods. Part II focuses on debt buyer lawsuits, particularly the systemic problems at the root of these lawsuits. In Part III, we highlight specific findings from a study of debt buyer lawsuits in New York City. We draw results from two data sets: (1) a 365-case sample of lawsuits brought by the 26 debt buyers who filed the greatest number of cases in New York City between January 2006 and July 2008 ("Court Sample"); and (2) a 451-case sample of callers to NEDAP's legal hotline who were sued by a creditor or debt buyer in 2008 ("Client Sample"). Finally, in Part IV, we recommend policy and legislative reforms to address the problems documented in this repor

The Structure of the DoAr 25 Circumstellar Disk

We present high spatial resolution (< 0.3" = 40$AU) Submillimeter Array observations of the 865 micron continuum emission from the circumstellar disk around the young star DoAr 25. Despite its bright millimeter emission, this source exhibits only a comparatively small infrared excess and low accretion rate, suggesting that the material and structural properties of the inner disk may be in an advanced state of evolution. A simple model of the physical conditions in the disk is derived from the submillimeter visibilities and the complete spectral energy distribution using a Monte Carlo radiative transfer code. For the standard assumption of a homogeneous grain size distribution at all disk radii, the results indicate a shallow surface density profile,$\Sigma \propto r^{-p}$ with p = 0.34, significantly less steep than a steady-state accretion disk (p = 1) or the often adopted minimum mass solar nebula (p = 1.5). Even though the total mass of material is large (M_d = 0.10 M_sun), the densities inferred in the inner disk for such a model may be too low to facilitate any mode of planet formation. However, alternative models with steeper density gradients (p = 1) can explain the observations equally well if substantial grain growth in the planet formation region (r < 40 AU) has occurred. We discuss these data in the context of such models with dust properties that vary with radius and highlight their implications for understanding disk evolution and the early stages of planet formation.Comment: ApJL in pres

Demand for Electricity Connection in Rural Areas : The Case of Kenya

A modern form of energy, in particular electricity for household use, is an important vehicle in alleviating poverty in developing countries. However, access and costs of connecting to this service for most poor in these countries is inconceivable. Policies promoting electricity connection in rural areas are known to be beneficial in improving the socio-economic and health well-being for households. This paper examines willingness to pay (WTP) for rural electrification connection in Kisumu district, Kenya, using the contingent valuation method (CVM). A nonparametric and a parametric model are employed to estimate WTP values for two electricity products: grid electricity (GE) and photovoltaic (PV) electricity. The results indicate that respondents are willing to pay more for GE services than PV and households favoured monthly connection payments over a lump sum amount. Some of the policies suggested in this paper include: subsidizing the connection costs for both sources of electricity, adjusting the payment periods, and restructuring the market ownership of providing rural electricity services.double bounded; contingent valuation; electricity connection; rural; willingness to pay (wtp)

Poverty rate and government income transfers: A spatial simultaneous equations approach

The poverty rate and income transfer are clearly correlated. However, not much research has attempted to determine the causal linkage between the two. Previous research has primarily focused on the poverty-reducing impact of income transfer. In this paper, we apply a simultaneous equation system of spatial regressions to uncover the spatial pattern of the relationship between the poverty rate and income transfer, using a sample of 3,001 U.S. counties. The results are in line with theoretical expectations; they provide evidence of a significant simultaneity effect between the poverty rate and income transfer. Our findings also confirm the presence of significant spatial autocorrelation. Contrary to previous studies, we find that more generous counties tend to do a better job of reducing poverty and that counties with more poor tend to be less generous, creating incentive for the poor to participate in the labor force. Furthermore, counties located in devolution states perform better in both poverty reduction and income transfer. These findings are missing from extant literature that focuses only on the poverty-reducing impact of welfare payments.endogeneity, income transfer, Poverty, SHAC, spatial econometrics,