Knowledge

Talk:Slutsky's theorem

Source đź“ť

74: 53: 173: 163: 142: 342:- The theorem, as stated, only makes sense if one of the variables X or Y is constant. Otherwise the distributions of X_n+Y_n, X+Y, X_n.Y_n and X.Y are not properly defined ! To have a proper definition of these distributions, one would need the joint distributions of the (X_n,Y_n)'s and of (X,Y). Now if one of the limiting variables, say Y, is actually a constant, then Y_n converges to Y in distribution if and only if it converges to that constant in probability. 22: 428:
The article says (in the notes section): "The theorem remains valid if we replace all convergences in distribution with convergences in probability (due to this property)." Here "this property" says that convergence in probability implies convergence in distribution. I think the reasoning here does
296:
Agreed. According to Fumio Hayashi's Econometrics textbook, Slutsky's Theorem says nothing about X_n and Y_n BOTH converging in distribution. Instead, if it is if X_n converges in distribution and Y_n converges in probability, then X_n + Y_n ... X_n*Y_n ... as stated already.
345:- In the third point (convergence of X_n/Y_n) it should be imposed that for n large enough, Y_n is almost surely non zero. Otherwise X_n/Y_n might not be defined on some non-negligible set of the probability space, even if Y \neq 0 a.s. 348:- To recap, the correct statement is : Let (Xn) and (Yn) be sequences of univariate random variables. If (Xn) converges in distribution to X and (Yn) converges in distribution to a constant a, then 124: 251:
The result in the article is not known as Slutsky's Theorem (that is a different result), but rather Slutsky's Lemma. The two results are cited often enough that the distinction should be made.
229: 351:* (Xn + Yn) converges in distribution to X + a, * (XnYn) converges in distribution to a*X, and * (Xn / Yn) converges in distribution to X / Y if Y \neq 0 almost surely. 429:
not work: to replace *all* occurences of "convergence in distribution" by "convergence in probability", we would need "this property" in both directions. --
501: 114: 516: 354:
Note that the convergence in distribution of a sequence of random variables (Yn) to a constant a is equivalent to the same convergence in probability.
219: 506: 195: 511: 90: 496: 328: 307: 258: 375:
Sorry, the last point is: (Xn / Yn) converges in distribution to (X / a) if a \neq 0 and Yn \neq 0 almost surely for n large enough.
288: 186: 147: 382: 361: 81: 58: 321:
Yes, I agree, this looks strange. One reference could be Bickel and Doksum, Mathematical statistics, theorem A.14.9, page 467.
477: 33: 332: 311: 262: 284: 386: 365: 39: 473: 280: 172: 73: 52: 465: 448: 378: 357: 324: 303: 276: 254: 21: 469: 194:
on Knowledge. If you would like to participate, please visit the project page, where you can join
89:
on Knowledge. If you would like to participate, please visit the project page, where you can join
178: 162: 141: 410: 444: 434: 490: 399: 397:
All these issues have been resolved, now the theorem’s statement is correct. ...
191: 481: 452: 438: 417: 390: 369: 336: 315: 266: 168: 86: 430: 443:@DniQ You're right; I have deleted the last half of that sentence. 300:
This is a very important distinction, but I'm not an expert.
15: 462:
The link to the counter example is not working anymore
411: 190:, a collaborative effort to improve the coverage of 85:, a collaborative effort to improve the coverage of 8: 424:Validity w.r.t. convergence in probability 136: 47: 272:The claim is wrong for general X_n, Y_n. 458:URL to footnote 4 is not working anymore 138: 49: 19: 7: 184:This article is within the scope of 79:This article is within the scope of 38:It is of interest to the following 502:Mid-importance Statistics articles 14: 517:Mid-priority mathematics articles 204:Knowledge:WikiProject Mathematics 207:Template:WikiProject Mathematics 171: 161: 140: 99:Knowledge:WikiProject Statistics 72: 51: 20: 507:WikiProject Statistics articles 224:This article has been rated as 119:This article has been rated as 102:Template:WikiProject Statistics 418:04:42, 13 September 2009 (UTC) 1: 439:15:59, 18 December 2019 (UTC) 198:and see a list of open tasks. 93:and see a list of open tasks. 512:B-Class mathematics articles 497:B-Class Statistics articles 267:16:34, 2 January 2013 (UTC) 533: 453:00:19, 20 April 2020 (UTC) 391:00:40, 12 April 2008 (UTC) 370:00:35, 12 April 2008 (UTC) 337:19:29, 12 March 2008 (UTC) 316:16:30, 11 March 2008 (UTC) 223: 156: 118: 67: 46: 482:14:32, 7 June 2022 (UTC) 230:project's priority scale 187:WikiProject Mathematics 82:WikiProject Statistics 28:This article is rated 210:mathematics articles 105:Statistics articles 179:Mathematics portal 34:content assessment 468:comment added by 393: 381:comment added by 372: 360:comment added by 339: 327:comment added by 318: 306:comment added by 293: 279:comment added by 257:comment added by 244: 243: 240: 239: 236: 235: 135: 134: 131: 130: 524: 484: 416: 413: 405: 402: 376: 355: 322: 301: 292: 273: 269: 212: 211: 208: 205: 202: 181: 176: 175: 165: 158: 157: 152: 144: 137: 125:importance scale 107: 106: 103: 100: 97: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 532: 531: 527: 526: 525: 523: 522: 521: 487: 486: 463: 460: 431:Dominique Unruh 426: 408: 403: 400: 352: 274: 252: 249: 247:old discussion… 209: 206: 203: 200: 199: 177: 170: 150: 104: 101: 98: 95: 94: 61: 32:on Knowledge's 29: 12: 11: 5: 530: 528: 520: 519: 514: 509: 504: 499: 489: 488: 459: 456: 425: 422: 421: 420: 350: 329:128.32.132.218 308:24.105.142.135 259:98.223.197.174 248: 245: 242: 241: 238: 237: 234: 233: 222: 216: 215: 213: 196:the discussion 183: 182: 166: 154: 153: 145: 133: 132: 129: 128: 121:Mid-importance 117: 111: 110: 108: 91:the discussion 77: 65: 64: 62:Mid‑importance 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 529: 518: 515: 513: 510: 508: 505: 503: 500: 498: 495: 494: 492: 485: 483: 479: 475: 471: 467: 457: 455: 454: 450: 446: 441: 440: 436: 432: 423: 419: 414: 407: 406: 396: 395: 394: 392: 388: 384: 380: 373: 371: 367: 363: 359: 349: 346: 343: 340: 338: 334: 330: 326: 319: 317: 313: 309: 305: 298: 294: 290: 286: 282: 278: 270: 268: 264: 260: 256: 246: 231: 227: 221: 218: 217: 214: 197: 193: 189: 188: 180: 174: 169: 167: 164: 160: 159: 155: 149: 146: 143: 139: 126: 122: 116: 113: 112: 109: 92: 88: 84: 83: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 464:— Preceding 461: 442: 427: 398: 374: 353: 347: 344: 341: 320: 299: 295: 281:91.19.96.104 271: 253:— Preceding 250: 226:Mid-priority 225: 185: 151:Mid‑priority 120: 80: 40:WikiProjects 377:—Preceding 356:—Preceding 323:—Preceding 302:—Preceding 275:—Preceding 201:Mathematics 192:mathematics 148:Mathematics 491:Categories 445:Thatsme314 383:81.57.2.37 362:81.57.2.37 96:Statistics 87:statistics 59:Statistics 478:contribs 466:unsigned 379:unsigned 358:unsigned 325:unsigned 304:unsigned 289:contribs 277:unsigned 255:unsigned 470:Irazall 228:on the 123:on the 30:B-class 36:scale. 404:pasha 474:talk 449:talk 435:talk 412:talk 387:talk 366:talk 333:talk 312:talk 285:talk 263:talk 220:Mid 115:Mid 493:: 480:) 476:• 451:) 437:) 409:» 401:st 389:) 368:) 335:) 314:) 291:) 287:• 265:) 472:( 447:( 433:( 415:» 385:( 364:( 331:( 310:( 283:( 261:( 232:. 127:. 42::

Index


content assessment
WikiProjects
WikiProject icon
Statistics
WikiProject icon
WikiProject Statistics
statistics
the discussion
Mid
importance scale
WikiProject icon
Mathematics
WikiProject icon
icon
Mathematics portal
WikiProject Mathematics
mathematics
the discussion
Mid
project's priority scale
unsigned
98.223.197.174
talk
16:34, 2 January 2013 (UTC)
unsigned
91.19.96.104
talk
contribs
unsigned

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑