Strategic Patenting and Software Innovation

Strategic patenting is widely believed to raise the costs of innovating,especially in industries characterised by cumulative innovation. This paperstudies the effects of strategic patenting on R&D, patenting and marketvalue in the computer software industry. We focus on two key aspects:patent portfolio size which affects bargaining power in patent disputes, andthe fragmentation of patent rights (.patent thickets.) which increases thetransaction costs of enforcement. We develop a model that incorporates botheffects, together with R&D spillovers. Using panel data for the period 1980-99, we find evidence that both strategic patenting and R&D spilloversstrongly affect innovation and market value of software firms.patents, anti-commons, patent thickets, R&D spillovers, marketvalue

The Evolving Food Chain: Competitive Effects of Wal-Marts Entry into the Supermarket Industry

We analyze the effect of Wal-Marts entry into the grocery market using a unique store-level price panel data set. We use OLS and two IV specifications to estimate the effect of Wal-Marts entry on competitors prices of 24 grocery items across several categories. Wal-Marts price advantage over competitors for these products averages approximately 10%. On average, competitors response to Wal-Marts entry is a price reduction of 11.2%, mostly due to smaller-scale competitors: the response of the big three supermarket chains (Albertsons, Safeway, and Kroger) is less than half that size. We confirm our results using a falsification exercises, in which we test for Wal-Marts effect on prices of services that it does not provide, such as movie tickets and dry cleaning services.Wal-Mart, Retail Prices, Supermarkets, Price Competition

HOUSEHOLD FOOD SPENDING BY SELECTED DEMOGRAPHICS IN THE 1990s

Average per-person total food expenditures, adjusted for inflation, declined about 7 percent between 1990 and 1998, from $2,189 to$2,037. This decline resulted primarily from the average at-home food expenditures per person declining by about 6 percent and the away-from-home food expenditures declining by about 8 percent. Price-adjusted food spending reflects changes in the real price of food as well as any quantity adjustments made by consumers. However, the national average masks the fact that some population subgroups had significantly higher or lower food expenditures than average. For example, while total food spending declined for all demographic groups except female-headed and Black households, these two demographic groups still had the lowest per capita spending. In contrast to this, per-person total food expenditures were greatest for households in the highest income quintile, for one-person households, and for households with heads between 55 and 64 years of age.Food expenditures, food spending, demographics, Consumer Expenditure Survey, Food Consumption/Nutrition/Food Safety,

DECOMPOSING RED MEAT, POULTRY, AND FISH EXPENDITURES INTO AGE, TIME, AND COHORT EFFECTS

This paper decomposes red meat, poultry, and fish consumption into cohort, age, and time effects. Younger cohorts spend less in real terms than older cohorts. These findings suggest strong implications for future consumption and nutrient intakes in the U.S.Consumer/Household Economics, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

FOOD-CONSUMPTION PATTERNS AMONG ELDERLY AGE GROUPS

Food Consumption/Nutrition/Food Safety,

Defining Markets That Involve Multi-Sided Platform Businesses: An Empirical Framework With an Application to Google's Purchase of DoubleClick

A multi-sided platform (MSP) serves as an intermediary for two or more groups of customers who are linked by indirect network effects. Recent research has found that MSPs are significant in many industries and that some standard economic results, such as the Lerner Index, do not apply to them, in material ways, without some significant modification to take linkages between the multiple sides into account. This article extends several key tools used for the analysis of mergers to situations in which one or more of the suppliers are MSPs. It shows that the application of traditional tools to mergers involving MSPs results in biases the direction of which depends on the particular tool being used and other conditions. It also extends these tools to the analysis of the merger of MSPs. The techniques are illustrated with an application to an acquisition by Google in the online advertising industry.

Image metadata estimation using independent component analysis and regression

In this paper, we describe an approach to camera metadata estimation using regression based on Independent Component Analysis (ICA). Semantic scene classification of images using camera metadata related to capture conditions has had some success in the past. However, different makes and models of camera capture different types of metadata and this severely hampers the application of this kind of approach in real systems that consist of photos captured by many different users. We propose to address this issue by using regression to predict the missing metadata from observed data, thereby providing more complete (and hence more useful) metadata for the entire image corpus. The proposed approach uses an ICA based approach to regression

Criticality in Charge-asymmetric Hard-sphere Ionic Fluids

Phase separation and criticality are analyzed in $z$:1 charge-asymmetric ionic fluids of equisized hard spheres by generalizing the Debye-H\"{u}ckel approach combined with ionic association, cluster solvation by charged ions, and hard-core interactions, following lines developed by Fisher and Levin (1993, 1996) for the 1:1 case (i.e., the restricted primitive model). Explicit analytical calculations for 2:1 and 3:1 systems account for ionic association into dimers, trimers, and tetramers and subsequent multipolar cluster solvation. The reduced critical temperatures, $T_c^*$ (normalized by $z$), \textit{decrease} with charge asymmetry, while the critical densities \textit{increase} rapidly with $z$. The results compare favorably with simulations and represent a distinct improvement over all current theories such as the MSA, SPB, etc. For $z$$\ne$1, the interphase Galvani (or absolute electrostatic) potential difference, $\Delta \phi(T)$, between coexisting liquid and vapor phases is calculated and found to vanish as $|T-T_c|^\beta$ when $T\to T_c-$ with, since our approximations are classical, $\beta={1/2}$. Above $T_c$, the compressibility maxima and so-called $k$-inflection loci (which aid the fast and accurate determination of the critical parameters) are found to exhibit a strong $z$-dependence.Comment: 25 pages, 14 figures; last update with typos corrected and some added reference

The Inverse Domino Effect: Are Economic Reforms Contagious?

This paper examines whether a country’s economic reforms are affected by reforms adopted by other countries. A simple model of economic reforms is developed to motivate the econometric work. Unsurprisingly, the model predicts that reforms are more likely when factors of production are internationally mobile and reforms are pursued in other economies. More interesting is the finding that reforms are not driven by greater trade openness. Using the change in the Index of Economic Freedom as the measure of market-liberalising reforms, we examine two issues. First, we examine whether economic reforms are ‘habit-forming’, and secondly, we identify the most important channels through which reforms are transmitted from country to country. For a panel of 144 countries and the years 1995-2006, we find little evidence that reforms are habit- forming, if anything there is a status quo bias. However, we do find evidence of the importance of reforms in other countries. Consistent with our model, international trade is not a vehicle for the diffusion of economic reforms, rather the most important mechanism is geographical or cultural proximity.Economic reforms; economic freedom; resource flow models; spatial interdependence

Cyclic Coloring of Plane Graphs with Maximum Face Size 16 and 17

Plummer and Toft conjectured in 1987 that the vertices of every 3-connected plane graph with maximum face size D can be colored using at most D+2 colors in such a way that no face is incident with two vertices of the same color. The conjecture has been proven for D=3, D=4 and D>=18. We prove the conjecture for D=16 and D=17