15,698 research outputs found
Quadratic engel curves and consumer demand
No full textThis paper presents a model of consumer demand that is consistent with the observed expenditure patterns of individual consumers in a long time series of expenditure surveys and is also able to provide a detailed welfare analysis of shifts in relative prices. A nonparametric analysis of consumer expenditure patterns suggests that Engel curves require quadratic terms in the logarithm of expenditure. While popular models of demand such as the Translog or the Almost Ideal Demand Systems do allow flexible price responses within a theoretically coherent structure, they have expenditure share Engel curves that are linear in the logarithm of total expenditure. We derive the complete class of integrable quadratic logarithmic expenditure share systems. A specification from this class is estimated on a large pooled data set of U.K. households. Models that fail to account for Engel curvature are found ro generate important distortions in the patterns of welfare losses associated with a tax increase
Nonparametric IV estimation of shape-invariant Engel curves
No full textThis paper concerns the identification and estimation of a shape-invariant Engel
curve system with endogenous total expenditure. The shape-invariant specification
involves a common shift parameter for each demographic group in a pooled
system of Engel curves. Our focus is on the identification and estimation of both
the nonparametric shape of the Engel curve and the parametric specification of the
demographic scaling parameters. We present a new identification condition, closely
related to the concept of bounded completeness in statistics. The estimation procedure
applies the sieve minimum distance estimation of conditional moment restrictions
allowing for endogeneity. We establish a new root mean squared convergence
rate for the nonparametric IV regression when the endogenous regressor has unbounded
support. Root-n asymptotic normality and semiparametric efficiency of
the parametric components are also given under a set of ‘low-level’ sufficient conditions.
Monte Carlo simulations shed lights on the choice of smoothing parameters
and demonstrate that the sieve IV estimator performs well. An application is made
to the estimation of Engel curves using the UK Family Expenditure Survey and
shows the importance of adjusting for endogeneity in terms of both the curvature
and demographic parameters of systems of Engel curves
Nonparametric IV estimation of shape-invariant Engel curves
No full textThis paper concerns the identification and estimation of a shape-invariant Engel curve system with endogenous total expenditure. The shape-invariant specification involves a common shift parameter for each demographic group in a pooled system of Engel curves. Our focus is on the identification and estimation of both the nonparametric shape of the Engel curve and the parametric specification of the demographic scaling parameters. We present a new identification condition, closely related to the concept of bounded completeness in statistics. The estimation procedure applies the sieve minimum distance estimation of conditional moment restrictions allowing for endogeneity. We establish a new root mean squared convergence rate for the nonparametric IV regression when the endogenous regressor has unbounded support. Root-n asymptotic normality and semiparametric efficiency of the parametric components are also given under a set of Ѭow-level' sufficient conditions. Monte Carlo simulations shed lights on the choice of smoothing parameters and demonstrate that the sieve IV estimator performs well. An application is made to the estimation of Engel curves using the UK Family Expenditure Survey and shows the importance of adjusting for endogeneity in terms of both the curvature and demographic parameters of systems of Engel curves.
II. M. Ch. Engel.
No full textII. M. Ch. Engel. In: Revue internationale de l'enseignement, tome 36, Juillet-Décembre 1898. p. 185
Engel-type subgroups and length parameters of finite groups
No full textLet g be an element of a finite group G and let Rn(g) be the subgroup generated by all the right Engel values [g,nx] over x?G. In the case when G is soluble we prove that if, for some n, the Fitting height of Rn(g) is equal to k, then g belongs to the (k+1)th Fitting subgroup Fk+1(G). For nonsoluble G, it is proved that if, for some n, the generalized Fitting height of Rn(g) is equal to k, then g belongs to the generalized Fitting subgroup F?f(k,m)(G) with f(k,m) depending only on k and m, where |g| is the product of m primes counting multiplicities. It is also proved that if, for some n, the nonsoluble length of Rn(g) is equal to k, then g belongs to a normal subgroup whose nonsoluble length is bounded in terms of k and m. Earlier similar generalizations of Baer's theorem (which states that an Engel element of a finite group belongs to the Fitting subgroup) were obtained by the first two authors in terms of left Engel-type subgroups.</p
Hyptiogastritinae Engel 2006
No full textKey to Genera of Hyptiogastritinae <p>1.Forewing with discal cell below level of M+Cu (i.e., 1Rs+M forming node with 1Rs, M+Cu, and 1Cu, and with 1M absent) (Fig. 4A); integument with areas of yellow maculation; moderate-sized wasps, approximately 4.5–5 mm in length [Archeofoenini, new tribe].. 2</p> <p> —Forewing with discal cell above level of M+Cu (i.e., 1M present, with 1Rs+M arising from “basal vein” and 1Cu in line with M+Cu); integument dark brown to black, without areas of maculation; small wasps, less than 4 mm in length [tribe Hyptiogastritini Engel]............................................................. <i>Hyptiogastrites</i> Cockerell</p> <p> 2.Compound eye large; mandible bidentate; forewing membrane uniformly clear; forewing 2Rs+M and 2Rs weakly angled, 2Rs subequal to 2Rs+M, r-rs equal to 2Rs, and 2M+Cu entirely absent; gena dark brown to black; metafemur dark brown except yellow at apex; metatibia yellow except at extreme apex and on majority of inner surface dark brown.............................................................. <i>Archeofoenus</i>, n. gen.</p> <p> —Compound eye small; mandible simple; forewing membrane infumate in apical half; forewing 2Rs+M and 2Rs distinctly angled, 2Rs shorter than 2Rs+M, r-rs longer than 2Rs, and minute 2M+Cu present (i.e., 1Rs slightly basad 1 Cua as figured by Cockerell, 1917b); gena entirely yellow; metafemur yellow except black at base; metatibia yellow except black at apex....................................................... <i>Protofoenus</i> Cockerell</p>Published as part of <i>Engel, Michael S., 2017, New Evanioid Wasps from the Cenomanian of Myanmar (Hymenoptera: Othniodellithidae, Aulacidae), with a Summary of Family-Group Names among Evanioidea, pp. 1-28 in American Museum Novitates 2017 (3871)</i> on page 11, DOI: 10.1206/3871.1, <a href="http://zenodo.org/record/5368793">http://zenodo.org/record/5368793</a>
Engel-type subgroups and length parameters of finite groups
No full textLet g be an element of a finite group G and let Rn(g) be the subgroup generated by all the right Engel values [g,nx] over x?G. In the case when G is soluble we prove that if, for some n, the Fitting height of Rn(g) is equal to k, then g belongs to the (k+1)th Fitting subgroup Fk+1(G). For nonsoluble G, it is proved that if, for some n, the generalized Fitting height of Rn(g) is equal to k, then g belongs to the generalized Fitting subgroup F?f(k,m)(G) with f(k,m) depending only on k and m, where |g| is the product of m primes counting multiplicities. It is also proved that if, for some n, the nonsoluble length of Rn(g) is equal to k, then g belongs to a normal subgroup whose nonsoluble length is bounded in terms of k and m. Earlier similar generalizations of Baer's theorem (which states that an Engel element of a finite group belongs to the Fitting subgroup) were obtained by the first two authors in terms of left Engel-type subgroups.</p
Some curiosites about the Engel method to estimate equivalence scales
No full textThis paper lends legitimacy to the food share as an indicator of welfare by demonstrating the conditions necessary in empirical work for the Engel method of estimating equivalence scales to provide an exact measure of welfare. In analogy to a money metric of utility, the Engel's food share is shown to be a “quantity metric of utility.”Engel method
Chlerogella mourella Engel
No full text<i>Chlerogella mourella</i> Engel <p>Figs 92–94, Map 3</p> <p> <i>Chlerogella mourella</i> Engel, 2003b: 135. Moure et al., 2007: 794.</p> <p> <b>Holotype.</b> ♀, ECUADOR: Napo, Sierra Azul, 2300 m, 21–22 April 1996, P. Hibbs, ex: flight intercept trap (SEMC).</p> <p> <b>Figures 92–94.</b> Holotype female of <i>Chlerogella mourella</i> Engel. <b>92</b> Lateral habitus <b>93</b> Lateral aspect of head <b>94</b> Facial aspect.</p> <p> <b>Paratype.</b> ECUADOR: 1♀, Napo, Cosanga Aragon, 8 November 1993, G. Onore (QCAZ).</p> <p> <b>Diagnosis.</b> <i>Chlerogella mourella</i> can be recognized readily by its relatively short malar space and its black head and mesosoma lacking metallic highlights (Figs 92–94).</p> <p> <b>Description.</b> From Engel (2003b), with minor emendations: <i>Female</i>: Total body length 10.6 mm; forewing length 8.72 mm. Head length 2.44 mm, width 1.84 mm. Clypeus beginning just above lower tangent of compound eyes. Malar space 19% compound eye length (malar length 0.3 mm, compound eye length 1.58 mm) (Figs 93–94). Upper interorbital distance 0.96 mm; lower interorbital distance 0.88 mm. Upper portion of pronotum medially depressed, not elongate, medially less than 0.25 times ocellar diameter in length; ventral portion of preëpisternal sulcus not broad, similar to scrobal sulcus and upper portion of preëpisternal sulcus; intertegular distance 1.5 mm; mesoscutellum weakly convex, not bigibbous. Basal vein distad cu-a by three times vein width; 1rs-m distad 1m-cu by 3.5 times vein width; 2rs-m distad 2m-cu by five times vein width, 2rs-m straight; first submarginal cell longer than combined lengths of second and third submarginal cells; second submarginal cell slightly narrowed anteriorly, anterior border of second submarginal cell along Rs shorter than that of third submarginal cell; posterior border of third submarginal cell about two times longer than anterior border. Distal hamuli arranged 2-1-2. Inner metatibial spur with six branches (not including apical portion of rachis).</p> <p>Clypeus and supraclypeal area granular with weak punctures separated by a puncture width; face granular with minute punctures in malar space separated by a puncture width; vertex weakly granular, becoming imbricate on gena and more strongly so by postgena. Pronotum weakly imbricate; mesoscutum granular; mesoscutellum and metanotum finely imbricate with faint punctures. Preëpisternum and mesepisternum granular with faint punctures separated by 2–3 times a puncture width; hypoepimeral area impunctate; metepisternum faintly imbricate. Propodeum strongly imbricate. Metasoma finely imbricate.</p> <p>Mandible black with reddish apex; labrum and remainder of head black to dark brown. Antenna dark brown except basal one-fifth and inner surface of scape amber. Mesosoma black (Fig. 92); tegula dark brown. Wing membranes lightly infumate; veins amber except Sc+R dark brown. Legs amber except dark brown on procoxa, inner surface of profemur, basal half of mesocoxa, inner base of mesofemur, basal threequarters of metacoxa, basal half of inner surface of metafemur. Metasomal TI amber, with dark brown band just beyond midline, band stopping a distance from apical margin equal to its width, apical margin amber; TII dark brown except basal and apical margins amber; TIII dark brown except apical margin amber; TIV–VI dark brown; SI–II amber; SIII amber except medial dark brown patch; SIV dark brown except apical margin yellowish; SV–VI dark brown.</p> <p>Pubescence golden except somewhat fuscous on TV–VI and SVI. Dense long, branched setae on discs of SI–II.</p> <p> <i>Male</i>: Unknown.</p>Published as part of <i>Engel, Michael, 2010, Revision of the Bee Genus Chlerogella (Hymenoptera, Halictidae), Part II: South American Species and Generic Diagnosis, pp. 1-100 in ZooKeys 47 (47)</i> on pages 58-60, DOI: 10.3897/zookeys.47.416, <a href="http://zenodo.org/record/576667">http://zenodo.org/record/576667</a>
Words of Engel type are concise in residually finite groups
No full textGiven a group-word w and a group G, the verbal subgroup w(G) is the one generated
by all w-values in G. The word w is said to be concise if w(G) is finite whenever the set
of w-values in G is finite. In the sixties P. Hall asked whether every word is concise but
later Ivanov answered this question in the negative. On the other hand, Hall’s question
remains wide open in the class of residually finite groups. In the present article we
show that various generalizations of the Engel word are concise in residually finite
groups
- …
