1,654 research outputs found
Consumer Boycotts: The Impact of the Iraq War on French Wine Sales in the U.S.
The French Opposition to the war in Iraq in early 2003, prompted calls for a boycott of French wine in the US. We measure the magnitude of consumers%u2019 participation in the boycott, and look at basic evidence of who participates. Conservative estimates indicate that the boycott resulted in 26% lower weekly sales at its peak, and 13% lower sales over the six month period that we estimate the boycott lasted for. These findings suggest that business should be concerned that their actions may provoke a boycott which hurts their profits. We also find that neither political preferences or media attention are important determinants of boycott participation.
Calorie Posting in Chain Restaurants
We study the impact of mandatory calorie posting on consumersâ purchase decisions, using detailed data from Starbucks. We find that average calories per transaction falls by 6%. The effect is almost entirely related to changes in consumersâ food choicesâthere is almost no change in purchases of beverage calories. There is no impact on Starbucks profit on average, and for the subset of stores located close to their competitor Dunkin Donuts, the effect of calorie posting is actually to increase Starbucks revenue. Survey evidence and analysis of commuters suggest the mechanism for the effect is a combination of learning and salience.Food Consumption/Nutrition/Food Safety,
The Welfare Effects of Ticket Resale
We develop an equilibrium model of ticket resale in which buyers' decisions in the primary market, including costly efforts to "arrive early" to buy underpriced tickets, are based on rational expectations of resale market outcomes. We estimate the parameters of the model using a novel dataset that combines transaction data from both the primary and secondary markets for a sample of major rock concerts. Our estimates indicate that while resale improves allocative efficiency, half of the welfare gain from reallocation is offset by increases in costly effort in the arrival game and transaction costs in the resale market.
Calorie Posting in Chain Restaurants
We study the impact of mandatory calorie posting on consumersâ purchase decisions, using detailed data from Starbucks. We find that average calories per transaction falls by 6%. The effect is almost entirely related to changes in consumersâ food choicesâthere is almost no change in purchases of beverage calories. There is no impact on Starbucks profit on average, and for the subset of stores located close to their competitor Dunkin Donuts, the effect of calorie posting is actually to increase Starbucks revenue. Survey evidence and analysis of commuters suggest the mechanism for the effect is a combination of learning and salience.
Absence of a metallicity effect for ultra-short-period planets
Ultra-short-period (USP) planets are a newly recognized class of planets with
periods shorter than one day and radii smaller than about 2 Earth radii. It has
been proposed that USP planets are the solid cores of hot Jupiters that lost
their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We
test this hypothesis by asking whether USP planets are associated with
metal-rich stars, as has long been observed for hot Jupiters. We find the
metallicity distributions of USP-planet and hot-Jupiter hosts to be
significantly different (), based on Keck spectroscopy of
Kepler stars. Evidently, the sample of USP planets is not dominated by the
evaporated cores of hot Jupiters. The metallicity distribution of stars with
USP planets is indistinguishable from that of stars with short-period planets
with sizes between 2--4~. Thus it remains possible that the USP
planets are the solid cores of formerly gaseous planets smaller than Neptune.Comment: AJ, in pres
Nearly Optimal Pricing for Multiproduct Firms
In principle, a multiproduct firm can set separate prices for all possible bundled combinations of its products (i.e., "mixed bundling"). However, this is impractical for firms with more than a few products, because the number of prices increases exponentially with the number of products. In this study we show that simple pricing strategies are often nearly optimal -- i.e., with surprisingly few prices a firm can obtain 99% of the profit that would be earned by mixed bundling. Specifically, we show that bundle-size pricing -- setting prices that depend only on the size of bundle purchased -- tends to be more profitable than offering the individual products priced separately, and tends to closely approximate the profits from mixed bundling. These findings are based on an array of numerical experiments covering a broad range of demand and cost scenarios, as well as an empirical analysis of the pricing problem for an 8-product firm (a theater company).
Resolved Depletion Zones and Spatial Differentiation of N2H+ and N2D+
We present a study on the spatial distribution of N2D+ and N2H+ in thirteen
protostellar systems. Eight of thirteen objects observed with the IRAM 30m
telescope show relative offsets between the peak N2D+ (J=2-1) and N2H+ (J=1-0)
emission. We highlight the case of L1157 using interferometric observations
from the Submillimeter Array and Plateau de Bure Interferometer of the N2D+
(J=3-2) and N2H+ (J=1-0) transitions respectively. Depletion of N2D+ in L1157
is clearly observed inside a radius of ~2000 AU (7") and the N2H+ emission is
resolved into two peaks at radii of ~1000 AU (3.5"), inside the depletion
region of N2D+. Chemical models predict a depletion zone in N2H+ and N2D+ due
to destruction of H2D+ at T ~ 20 K and the evaporation of CO off dust grains at
the same temperature. However, the abundance offsets of 1000 AU between the two
species are not reproduced by chemical models, including a model that follows
the infall of the protostellar envelope. The average abundance ratios of N2D+
to N2H+ have been shown to decrease as protostars evolve by Emprechtinger et
al., but this is the first time depletion zones of N2D+ have been spatially
resolved. We suggest that the difference in depletion zone radii for N2H+ and
N2D+ is caused by either the CO evaporation temperature being above 20 K or an
H2 ortho-to-para ratio gradient in the inner envelope.Comment: Accepted to ApJ. 44 pages 13 Figure
The California-Kepler Survey. II. Precise Physical Properties of 2025 Kepler Planets and Their Host Stars
We present stellar and planetary properties for 1305 Kepler Objects of
Interest (KOIs) hosting 2025 planet candidates observed as part of the
California-Kepler Survey. We combine spectroscopic constraints, presented in
Paper I, with stellar interior modeling to estimate stellar masses, radii, and
ages. Stellar radii are typically constrained to 11%, compared to 40% when only
photometric constraints are used. Stellar masses are constrained to 4%, and
ages are constrained to 30%. We verify the integrity of the stellar parameters
through comparisons with asteroseismic studies and Gaia parallaxes. We also
recompute planetary radii for 2025 planet candidates. Because knowledge of
planetary radii is often limited by uncertainties in stellar size, we improve
the uncertainties in planet radii from typically 42% to 12%. We also leverage
improved knowledge of stellar effective temperature to recompute incident
stellar fluxes for the planets, now precise to 21%, compared to a factor of two
when derived from photometry.Comment: 13 pages, 4 figures, 4 tables, accepted for publication in AJ; full
versions of tables 3 and 4 are include
Distilled Feature Fields Enable Few-Shot Language-Guided Manipulation
Self-supervised and language-supervised image models contain rich knowledge
of the world that is important for generalization. Many robotic tasks, however,
require a detailed understanding of 3D geometry, which is often lacking in 2D
image features. This work bridges this 2D-to-3D gap for robotic manipulation by
leveraging distilled feature fields to combine accurate 3D geometry with rich
semantics from 2D foundation models. We present a few-shot learning method for
6-DOF grasping and placing that harnesses these strong spatial and semantic
priors to achieve in-the-wild generalization to unseen objects. Using features
distilled from a vision-language model, CLIP, we present a way to designate
novel objects for manipulation via free-text natural language, and demonstrate
its ability to generalize to unseen expressions and novel categories of
objects.Comment: Project website at https://f3rm.csail.mit.ed
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