# Package inputenc error - trying to decipher the log

I got an inputenc error. From what I understand, this means that I have used an undefined character. However, I cannot find that character in my document. I need help in understanding the log messages. Here is the part of the log that seems relevant:

...

Overfull \hbox (3.69263pt too wide) in paragraph at lines 167--174 \T1/cmtt/m/n/10 http://www.worldscientific.com/doi/abs/10.1142/S021884300900205 1\T1/cmr/m/n/10 . []

[36] Underfull \hbox (badness 10000) in paragraph at lines 176--182 []\T1/cmr/m/n/10 Z. Lan-dau, O. Reid, and I. Yer-shov. A fair di-vi-sion so-lu - []

Underfull \hbox (badness 6893) in paragraph at lines 176--182 \T1/cmr/m/n/10 tion to the prob-lem of re-dis-trict-ing. \T1/cmr/m/it/10 So-ci al Choice and Wel- []

Underfull \hbox (badness 2809) in paragraph at lines 176--182 \T1/cmr/m/it/10 fare\T1/cmr/m/n/10 , 32(3):479--492, 2009. doi: 10.1007/s00355 -008-0336-6. URL []

! Package inputenc Error: Keyboard character used is undefined (inputenc) in inputencoding latin9'.

See the inputenc package documentation for explanation. Type H <return> for immediate help. ... l.192 ...Fair division and collective welfare‏}} . You need to provide a definition with \DeclareInputText or \DeclareInputMath before using this key.

! Package inputenc Error: Keyboard character used is undefined (inputenc) in inputencoding latin9'.

See the inputenc package documentation for explanation. Type H <return> for immediate help. ... l.192 ...Fair division and collective welfare‏}} . You need to provide a definition with \DeclareInputText or \DeclareInputMath before using this key.

Overfull \hbox (575.80292pt too wide) in paragraph at lines 191--196 \T1/cmtt/m/n/10 http://books.google.com/books?hl=iw&#38;lr=&#38;id=qQXtEnb2B2cC &#38;oi=fnd&#38;pg=PA1&#38;dq=fair+division+incremental&#38;ots=mAHSbq1bK7&#38; sig=xmB3IOFf5gFGIxPQk_k7w3Roed8\T1/cmr/m/n/10 . []

...


And here is another possibly related section - it's a record from my BibTex file:

@book{Moulin2004Fair,
abstract = {{The concept of fair division is as old as civil society itself. Aristotle's "equal treatment of equals" was the first step toward a formal definition of distributive fairness. The concept of collective welfare, more than two centuries old, is a pillar of modern economic analysis. Reflecting fifty years of research, this book examines the contribution of modern microeconomic thinking to distributive justice. Taking the modern axiomatic approach, it compares normative arguments of distributive justice and their relation to efficiency and collective welfare. The book begins with the epistemological status of the axiomatic approach and the four classic principles of distributive justice: compensation, reward, exogenous rights, and fitness. It then presents the simple ideas of equal gains, equal losses, and proportional gains and losses. The book discusses three cardinal interpretations of collective welfare: Bentham's "utilitarian" proposal to maximize the sum of individual utilities, the Nash product, and the egalitarian leximin ordering. It also discusses the two main ordinal definitions of collective welfare: the majority relation and the Borda scoring method. The Shapley value is the single most important contribution of game theory to distributive justice. A formula to divide jointly produced costs or benefits fairly, it is especially useful when the pattern of externalities renders useless the simple ideas of equality and proportionality. The book ends with two versatile methods for dividing commodities efficiently and fairly when only ordinal preferences matter: competitive equilibrium with equal incomes and egalitarian equivalence. The book contains a wealth of empirical examples and exercises.

-

CONTENTS:
1 Microeconomic Foundations
3 Cardinal
6 Ordinal
14 Externalities and Fair Division9
15 Private versus Public Contracts13
16 Organization and Overview of ...15
17 Introduction to the Literature18
Fair Distribution21
22 A Simple Model of Fair Distri...27
23 Contested Garment Method37
24 Equal Sacrifice in Taxation41
25 SumFitness and Equality44
26 Introduction to the Literature51
Exercises to Chapter 252
Cardinal Welfarism63
33 Egalitarianism and the Leximi...70
34 Comparing Classical Utilitari...76
35 Failures of Monotonicity81
36 Bargaining Compromise86
37 Introduction to the Literature95
Exercises to Chapter 396
Voting and Social Choice107
42 Condorcet versus Borda110
43 Voting over Resource Allocation116
44 SinglePeaked Preferences118
45 Intermediate Preferences122
46 Preference Aggregation and Ar...126
47 Introduction to the Literature130
Exercises to Chapter 4131
The Shapley Value139
Definition143
53 The Standalone Test and Stand...147
54 Standalone Surplus156
55 Axiomatizations of the Shaple...159
56 Introduction to the Literature162
Exercises to Chapter 5163
Managing the Commons169
62 Constant Returns to Scale173
Three Interpretations175
Decreasing Returns184
65 Increasing Returns190
66 Axiomatic Comparison of the T...199
67 Introduction to the Literature208
Exercises to Chapter 6209
72 Imperfect Competition228
73 Destructive Competition232
74 No Envy and the Assignment Pr...235
75 The CEEI and Egalitarian Equi...240
76 Axiomatics of Fair Division248
77 Introduction to the Literature251
Exercises to Chapter 7252
A Glossary of Definitions and Re...261
277 References}},
author = {Moulin, Herve},
citeulike-article-id = {12226526},
keywords = {externalities, fair-division, review, social-choice, voting},
posted-at = {2013-03-30 22:19:59},
priority = {5},
publisher = {MIT Press},
title = {{Fair division and collective welfare‏}},
year = {2004}
}

• You have a stray Unicode character (U+200F) that becomes <E2><80><8F> in UTF-8 and characters <80> and <8F> trigger the errors. The stray character is between welfare and }. – egreg Oct 5 '13 at 19:50
• You must be a wizard. You see the unseen. – Erel Segal-Halevi Oct 5 '13 at 20:47
• I just copied the possible culprit from the clues you gave and pasted it into the upper box in rishida.net/tools/conversion, asking then to convert. And, presto, a U+200F appeared in the Unicode U+hex box. – egreg Oct 5 '13 at 20:50

Such kind of errors usually depends on otherwise invisible characters.

Proceed with method and try isolating the problem; in this case the message appears twice and in both instances the error message tells you that TeX is reading

Fair division and collective welfare‏}}


which evidently comes from the .bbl file and the bibliography item you report.

So go to the .bib file and copy the possible culprit, checking for invisible characters.

A good method for analyzing a text for invisible characters is to paste it into the upper box in the web page Unicode code converter and ask for conversion. Here's a snapshot of what I got:

You can see in the “Unicode U+hex notation” box the U+200F that shows finally where the problem is. Somehow the Unicode character “U+200F RIGHT-TO-LEFT MARK” sneaked in. Remove it (retyping the line might reveal necessary) and retry.

Why two messages? You're using Latin-1, and the UTF-8 representation of U+200F is three bytes, numbers 226, 128 and 143. In Latin-1, character 226 is â, while 128 and 143 have no meaning and so they raise an error each.

• I still think you are a wizard. But now I also have your magic wand :) – Erel Segal-Halevi Oct 5 '13 at 23:25