Alternative Methods of Increasing the Precision of Weighted Repeat Sales House Prices Indices

Weighted repeat sales house price indices have become one of the primary indicators used to identify housing market conditions and to estimate the amount of equity homeowners have gained through house price appreciation. The primary reason for the acceptance of this methodology is that it derives a location specific (typically, census division, state or metropolitan area) average change in house prices from repeated observations of individual house prices. It is this repeat attribute that allows repeat sales price indices to claim that it is a preferable index which does a better job of holding quality constant. The amount of time between the two observed prices for a single property is determined by when the home transacts. Some homes transact twice in a period of months and others do not transact for decades. It is likely that individual house price appreciation rates vary from the mean appreciation rate, as estimated by the index, in a systematic fashion. In general, the longer the time between transactions the more variance there is in individual house price appreciation. This paper extends this concept to include new dimensions. For instance, houses that appreciate faster than the mean, as estimated by the index for that location, may experience a different variation structure than homes that appreciate slower. This process can be viewed as an asymmetric treatment of the variance of house price appreciation around the estimated index. In addition, the variance of expensive and affordable homes may also be different and time varying. This paper finds evidence that adding the dimensions of price tiers and asymmetry to the variance estimate has merit and does affect the estimated index as well as homeowner equity estimates. Homeowner equity estimates are especially sensitive to these added dimensions because they depend on both the revised index and the estimated variances, which are specific to each dimension considered—time between transaction, asymmetry, and price tier.     

Adjusting for Non-Linear Age Effects in the Repeat Sales Index

A true constant quality real estate price index should measure the general change in price level free from any change in quality over time. In recent years, the repeat-sales method has been widely used to construct constant quality property price indices. Since buildings depreciate over time, a simple repeat-sales index would underestimate the growth in property prices. The major problem of controlling the effects of age constant in a repeat-sales model arises from the exact multicollinearity between the age variable and the time dummy variables. In this study, we derive a solution that is theoretically sound and practical by allowing the age effects to be non-linear. In case of leasehold properties, we further incorporated interest rates into the model because the effects of age on real estate prices depend theoretically on interest rates. A sample of residential units in Hong Kong sold more than once from Quarter 2 of 1991 to Quarter 1 of 2001 (more than 11,000 repeat sales pairs) are used for the empirical analysis.     

Temporal Aggregation in Repeated Sales Models

Over the years, repeated sales models have come to wide and even commercial use. However, considering the subset of dwellings sold twice entail several challenges. Small sample problems constitute a special concern in repeated sales models, since sample sizes tend to be smaller than hedonic methods based on all transactions in a given period of time. Moreover, a cluster of observations in one time period does not only influence the index corresponding to that particular time period, but all other estimated indexes. A simulation approach is used to study the interplay between sample size and temporal aggregation. The analysis shows that serious mis-measurements may occur even in cases where the statistical diagnostic tools like R ² and t-values and empiric standard deviations indicate good explanatory power. However, the risk of serious biases driven by sparse data sets tends to be small, even if the actual estimated price curve show signs of under-smoothing. Mis-measured curves have unstable estimates with respect to temporal aggregation. Two repeated models, one with a slightly finer time partition achieved by adding one more time dummy, used on the same sample can alter the index estimate at a given time with as much at 10–15%. The simulations reveal that varying temporal aggregation is a powerful diagnostic tool and should be employed routinely. The last part of the paper shows that choosing an appropriate temporal aggregation involves more than merely a balance between under-smoothing and over-smoothing. Efficiency questions tend to be better addressed by a higher temporal aggregation, than a good overall estimation of the price curve alone calls for.      

Separating the Age Effect from a Repeat Sales Index: Land and Structure Decomposition

Since real estate is heterogeneous and not all its quality attributes are observable, the repeat sales model pioneered by Bailey et al. (1963) has become one of the standard methods to estimate a constant-quality price index. The model, however, fails to adjust for depreciation, as age and time between sales have an exact linear relationship. This paper proposes a new method to estimate an age-adjusted repeat sales index by decomposing property value into land and structure components. As depreciation is more relevant to the structure than land, the property’s depreciation rate should depend on the relative size of land and structure. The larger the land component, the lower the depreciation rate of the property. This new method is applied to property transactions in Hong Kong and Tokyo. Hong Kong is shown to have a higher depreciation rate based on a fixed structure-to-property value ratio, while the resulting age adjustment is larger in Tokyo because its land value has shrunken over time.     

Comparison of Option Prices in Semimartingale Models

In this paper we generalize the recent comparison results of El Karoui et al. (Math Finance 8:93–126, 1998), Bellamy and Jeanblanc (Finance Stoch 4:209–222, 2000) and Gushchin and Mordecki (Proc Steklov Inst Math 237:73–113, 2002) to d-dimensional exponential semimartingales. Our main result gives sufficient conditions for the comparison of European options with respect to martingale pricing measures. The comparison is with respect to convex and also with respect to directionally convex functions. Sufficient conditions for these orderings are formulated in terms of the predictable characteristics of the stochastic logarithm of the stock price processes. As examples we discuss the comparison of exponential semimartingales to multivariate diffusion processes, to stochastic volatility models, to Lévy processes, and to diffusions with jumps. We obtain extensions of several recent results on nontrivial price intervals. A crucial property in this approach is the propagation of convexity property. We develop a new approach to establish this property for several further examples of univariate and multivariate processes.     

Estimating Volatility Persistence in Oil Prices Under Structural Breaks

Policy makers and financial market participants are interested in knowing how shocks affect the volatility of oil prices over time. We accurately compute the volatility persistence by incorporating endogenously determined structural breaks into a GARCH model. Contrary to previous findings, we find that oil shocks dissipate very quickly but have a strong initial impact. Understanding this behavior is not only important for derivative valuation and hedging decisions but for broader financial markets and the overall economy, for which there are significant consequences.     

Gulf Views: Toward a Better Understanding of Viewshed Scope in Hedonic Property Models

This study examines the influence of Gulf of Mexico views on residential home sales prices in Pinellas County, Florida. We utilize Light Detection and Ranging (lidar) data to construct four continuous measures of Gulf of Mexico views—the total view, the maximum view segment, the mean view segment, and proximity to view content. Our results illustrate that residential property owners have a higher marginal willingness-to-pay for larger total views and larger continuous view segments. Results also indicate that the proximity of homes to the view content influences view valuations.     

Additive Hedonic Regression Models with Spatial Scaling Factors: An Application for Rents in Vienna

This paper is motivated by two common challenges in hedonic price modeling: nonlinear price functions, which require flexible modeling approaches, and the inherent spatial heterogeneity in real estate markets. We apply additive mixed regression models (AMM) to estimate hedonic price equations for rents in Vienna. Non-linear effects of continuous covariates as well as a smooth time trend are modeled non-parametrically through P-splines. Unobserved district-specific heterogeneity is modeled in two ways: First, by location specific intercepts with the postal code serving as a location variable. Second, in order to permit spatial variation in the nonlinear price gradients, we introduce multiplicative scaling factors for nonlinear covariates. This allows highly nonlinear implicit price functions to vary within a regularized framework, accounting for district-specific spatial heterogeneity, which leads to a considerable improvement of model quality and predictive power. Our findings provide insight into the spatially heterogeneous structure of price gradients in Vienna, showing substantial spatial variation. Accounting for spatial heterogeneity in a very general way, this approach permits higher accuracy in prediction and allows for location-specific nonlinear rent index construction.     

Heterogeneous Expectations,Restrictions on Short Sales,and Equilibrium Asset Prices

Under heterogeneous expectations, the mean–variance model of capital market equilibrium is employed to determine the effect restricting short sales has on equilibrium asset prices. Two equivalent markets differing only with respect to short sale restrictions are compared. It is shown that, in general, risky asset prices can either rise or fall due to short sale constraints. However, under a homogeneity of beliefs for the covariance matrix of future prices, short sale constraints will only increase risky asset prices.     

Expectations Models of Asset Prices: A Survey of Theory

This paper identifies restrictions on preferences under which various classes of “expectations” theories of asset prices—i.e., uncertainty models of asset prices which coincide with the corresponding certainty theory except that expected future prices replace actual future prices—are valid. Major classes of expectations models surveyed are martingale models, the expectations hypothesis of the term structure of interest rates, and models of exhaustible resources and futures markets. In each case the required restriction is related to the assumptiono f risk—neutrality, but the precise nature of the required restriction is shown to differ significantly among the various classes of expectations theories.     

The Hierarchical Repeat Sales Model for Granular Commercial Real Estate and Residential Price Indices

This paper concerns the estimation of granular property price indices in commercial real estate and residential markets. We specify and apply a repeat sales model with multiple stochastic log price trends having a hierarchical additive structure: One common log price trend and cluster specific log price trends in deviation from the common trend. Moreover, we assume that the error terms potentially have a heavy tailed (t) distribution to effectively deal with outliers. We apply the hierarchical repeat sales model on commercial properties in the Philadelphia/Baltimore region and on residential properties in a small part of Amsterdam. The results show that the hierarchical repeat sales model provides reliable indices on a very detailed level based on a small number of observations. The estimated degrees of freedom for the t-distribution is small, largely rejecting the commonly made assumption of normality of the error term.     

Developing a House Price Index for The Netherlands: A Practical Application of Weighted Repeat Sales

This paper describes the development of a house price index that has been introduced in May 2005 in The Netherlands. This monthly index, called Woningwaarde Index Kadaster (House Price Index Kadaster), is designed to detect changes in the price of the overall stock of owner-occupied homes. Fifty-five indices are calculated: one overall index, four regional indices, 12 provincial indices and 38 indices based on combinations of region/province and dwelling type. We used Case and Shiller’s geometric Weighted Repeat Sales Model to calculate monthly house price indices. We used recorded data on the sales of over 500,000 owner-occupied homes in The Netherlands, all representing repeat sales between January 1993 and December 2006. The accuracy of the index was determined using the 95% confidence interval. We observed that accuracy might become a problem in smaller sub samples. Revision volatility was explored by comparing the index values computed from all available data until December 2005 with the index values computed from the data available until December 2006. Our analysis showed that revision volatility does not seem to be a major problem to the index. We also explored heteroskedasticity in the Repeat Sales method but did not find conclusive evidence for the proposed heteroskedasticity. Given our target (a geometric mean index value) and the characteristics of the dataset (very large but without property characteristics) the Repeat Sales Method seems to be adequate for calculating a house price index for The Netherlands.

The Effects of Attributes on the Repeat Sales Pattern of Residential Property in Hong Kong

There has been copious research work on the development of house price models and the construction of house price indices. However, results in some studies revealed that the accuracy of such indices could be subject to selection bias when using only information from a sample of sold properties to estimate value movements for the entire housing stock. In particular, estimated house price appreciation is usually systematically higher among properties that change hands more frequently. It therefore suggests that the determination of important factors affecting the transaction frequency or intensity of a housing unit should be a more fundamental research question. This paper examines the possible factors that determine the popularity of residential unit by means of a repeated sales pattern. The Poisson regression model and event history analysis techniques are employed to assess the effect of attributes on transaction frequency and intensity. The event history analyses technique can take account of transaction-specific as well as time-dependent covariates, and therefore is recommended for analyzing repeated sales data in a real estate market. All transaction records during the period 1993–2000 from the Land Registry of one of the most popular residential estates in Hong Kong were used to illustrate the method. Unlike a response to favorable transaction price, good quality units do not necessarily inherently display a high transaction frequency. Rather, units of average quality are more likely to be transactionally active.     

Does the Measurement of Property and Structural Characteristics Affect Estimated Implicit Prices for Environmental Amenities in a Hedonic Model?

Hedonic models are commonly used to estimate marginal willingness to pay for environmental amenities. These studies utilize variables that are assumed to be measured without error (such as the square footage of the lot or the number of bedrooms) and proxy variables (such as neighborhood or school quality). Lot and structural characteristics may in fact be measured with error. Potential sources of error include inaccurate measures and inconsistent updating. We investigate the effect of using tax-assessor data versus survey data from purchasers to estimate the implicit price of an environmental amenity, lake-water clarity. Convergent validity of the implicit price for water clarity is established if the town and survey data provide statistically indistinguishable estimates of implicit prices for this amenity. Overall, the town-office and survey data on property characteristics were not statistically different in three of the four market groupings examined, which suggests that the traditional municipal sources of these data may not contain substantial measurement error. Furthermore, convergent validity is satisfied in all four market areas. However, differences in computed implicit prices of clarity in two of the market areas are large enough that policy decisions for environmental quality could be affected by the source of the lot and structural data.     

Post-IPO Directors' Sales and Reissuing Activity: An Empirical Test of IPO Signalling Models

Signalling models of IPO underpricing argue that owners of high-quality firms signal firm quality by underpricing shares sold at the IPO and retaining a large equity stake because they benefit from IPO signalling by selling further shares in the aftermarket at a higher share price. This hypothesis is tested by examining whether the probabilities and volumes of subsequent share issues or insider sales are related to the proposed IPO signals. There is evidence that post-IPO share issuance is related to initial returns, but the same is not true for insider selling. Moreover, little evidence is found to support the view that the proportion of equity retained by initial owners is an IPO signal. Therefore, the signalling hypothesis is rejected.     

合规管理模式的变迁路径及其启示

从20世纪90年代初开始,不少发达国家和地区的监管机构先后出台了有关银行业机构内部合规管理的规定。2003年10月,巴塞尔银行监管委员会发布了《银行内部合规部门》的咨询文件;2005年4月29日,巴塞尔银行监管委员会又发布了《合规与银行内部合规部门》的高级文件。至此,国际社会基本确立了银行业合规管理的新模